+import ast
import asyncio
-import pickle
-from asyncio.base_events import BaseEventLoop
from concurrent.futures import Executor, ProcessPoolExecutor
-from enum import Enum, Flag
-from functools import partial, wraps
-import keyword
+from contextlib import contextmanager
+from datetime import datetime
+from enum import Enum
+from functools import lru_cache, partial, wraps
+import io
+import itertools
import logging
-from multiprocessing import Manager
+from multiprocessing import Manager, freeze_support
import os
from pathlib import Path
-import re
-import tokenize
+import pickle
+import regex as re
import signal
import sys
+import tempfile
+import tokenize
+import traceback
from typing import (
Any,
Callable,
Collection,
Dict,
+ Generator,
Generic,
Iterable,
Iterator,
Sequence,
Set,
Tuple,
- Type,
TypeVar,
Union,
cast,
)
+from typing_extensions import Final
+from mypy_extensions import mypyc_attr
from appdirs import user_cache_dir
-from attr import dataclass, Factory
+from dataclasses import dataclass, field, replace
import click
+import toml
+from typed_ast import ast3, ast27
+from pathspec import PathSpec
# lib2to3 fork
from blib2to3.pytree import Node, Leaf, type_repr
from blib2to3 import pygram, pytree
from blib2to3.pgen2 import driver, token
+from blib2to3.pgen2.grammar import Grammar
from blib2to3.pgen2.parse import ParseError
+from _black_version import version as __version__
-__version__ = "18.5b1"
DEFAULT_LINE_LENGTH = 88
-DEFAULT_EXCLUDES = (
- r"/(\.git|\.hg|\.mypy_cache|\.tox|\.venv|_build|buck-out|build|dist)/"
-)
+DEFAULT_EXCLUDES = r"/(\.eggs|\.git|\.hg|\.mypy_cache|\.nox|\.tox|\.venv|\.svn|_build|buck-out|build|dist)/" # noqa: B950
DEFAULT_INCLUDES = r"\.pyi?$"
CACHE_DIR = Path(user_cache_dir("black", version=__version__))
# types
FileContent = str
Encoding = str
+NewLine = str
Depth = int
NodeType = int
LeafID = int
Priority = int
Index = int
LN = Union[Leaf, Node]
-SplitFunc = Callable[["Line", bool], Iterator["Line"]]
+SplitFunc = Callable[["Line", Collection["Feature"]], Iterator["Line"]]
Timestamp = float
FileSize = int
CacheInfo = Tuple[Timestamp, FileSize]
class NothingChanged(UserWarning):
- """Raised by :func:`format_file` when reformatted code is the same as source."""
+ """Raised when reformatted code is the same as source."""
class CannotSplit(Exception):
- """A readable split that fits the allotted line length is impossible.
+ """A readable split that fits the allotted line length is impossible."""
- Raised by :func:`left_hand_split`, :func:`right_hand_split`, and
- :func:`delimiter_split`.
- """
+class InvalidInput(ValueError):
+ """Raised when input source code fails all parse attempts."""
-class FormatError(Exception):
- """Base exception for `# fmt: on` and `# fmt: off` handling.
- It holds the number of bytes of the prefix consumed before the format
- control comment appeared.
- """
+class WriteBack(Enum):
+ NO = 0
+ YES = 1
+ DIFF = 2
+ CHECK = 3
- def __init__(self, consumed: int) -> None:
- super().__init__(consumed)
- self.consumed = consumed
+ @classmethod
+ def from_configuration(cls, *, check: bool, diff: bool) -> "WriteBack":
+ if check and not diff:
+ return cls.CHECK
- def trim_prefix(self, leaf: Leaf) -> None:
- leaf.prefix = leaf.prefix[self.consumed :]
+ return cls.DIFF if diff else cls.YES
- def leaf_from_consumed(self, leaf: Leaf) -> Leaf:
- """Returns a new Leaf from the consumed part of the prefix."""
- unformatted_prefix = leaf.prefix[: self.consumed]
- return Leaf(token.NEWLINE, unformatted_prefix)
+class Changed(Enum):
+ NO = 0
+ CACHED = 1
+ YES = 2
-class FormatOn(FormatError):
- """Found a comment like `# fmt: on` in the file."""
+class TargetVersion(Enum):
+ PY27 = 2
+ PY33 = 3
+ PY34 = 4
+ PY35 = 5
+ PY36 = 6
+ PY37 = 7
+ PY38 = 8
+
+ def is_python2(self) -> bool:
+ return self is TargetVersion.PY27
+
+
+PY36_VERSIONS = {TargetVersion.PY36, TargetVersion.PY37, TargetVersion.PY38}
+
+
+class Feature(Enum):
+ # All string literals are unicode
+ UNICODE_LITERALS = 1
+ F_STRINGS = 2
+ NUMERIC_UNDERSCORES = 3
+ TRAILING_COMMA_IN_CALL = 4
+ TRAILING_COMMA_IN_DEF = 5
+ # The following two feature-flags are mutually exclusive, and exactly one should be
+ # set for every version of python.
+ ASYNC_IDENTIFIERS = 6
+ ASYNC_KEYWORDS = 7
+ ASSIGNMENT_EXPRESSIONS = 8
+ POS_ONLY_ARGUMENTS = 9
+
+
+VERSION_TO_FEATURES: Dict[TargetVersion, Set[Feature]] = {
+ TargetVersion.PY27: {Feature.ASYNC_IDENTIFIERS},
+ TargetVersion.PY33: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS},
+ TargetVersion.PY34: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS},
+ TargetVersion.PY35: {
+ Feature.UNICODE_LITERALS,
+ Feature.TRAILING_COMMA_IN_CALL,
+ Feature.ASYNC_IDENTIFIERS,
+ },
+ TargetVersion.PY36: {
+ Feature.UNICODE_LITERALS,
+ Feature.F_STRINGS,
+ Feature.NUMERIC_UNDERSCORES,
+ Feature.TRAILING_COMMA_IN_CALL,
+ Feature.TRAILING_COMMA_IN_DEF,
+ Feature.ASYNC_IDENTIFIERS,
+ },
+ TargetVersion.PY37: {
+ Feature.UNICODE_LITERALS,
+ Feature.F_STRINGS,
+ Feature.NUMERIC_UNDERSCORES,
+ Feature.TRAILING_COMMA_IN_CALL,
+ Feature.TRAILING_COMMA_IN_DEF,
+ Feature.ASYNC_KEYWORDS,
+ },
+ TargetVersion.PY38: {
+ Feature.UNICODE_LITERALS,
+ Feature.F_STRINGS,
+ Feature.NUMERIC_UNDERSCORES,
+ Feature.TRAILING_COMMA_IN_CALL,
+ Feature.TRAILING_COMMA_IN_DEF,
+ Feature.ASYNC_KEYWORDS,
+ Feature.ASSIGNMENT_EXPRESSIONS,
+ Feature.POS_ONLY_ARGUMENTS,
+ },
+}
-class FormatOff(FormatError):
- """Found a comment like `# fmt: off` in the file."""
+@dataclass
+class Mode:
+ target_versions: Set[TargetVersion] = field(default_factory=set)
+ line_length: int = DEFAULT_LINE_LENGTH
+ string_normalization: bool = True
+ is_pyi: bool = False
-class WriteBack(Enum):
- NO = 0
- YES = 1
- DIFF = 2
+ def get_cache_key(self) -> str:
+ if self.target_versions:
+ version_str = ",".join(
+ str(version.value)
+ for version in sorted(self.target_versions, key=lambda v: v.value)
+ )
+ else:
+ version_str = "-"
+ parts = [
+ version_str,
+ str(self.line_length),
+ str(int(self.string_normalization)),
+ str(int(self.is_pyi)),
+ ]
+ return ".".join(parts)
-class Changed(Enum):
- NO = 0
- CACHED = 1
- YES = 2
+# Legacy name, left for integrations.
+FileMode = Mode
+
+
+def supports_feature(target_versions: Set[TargetVersion], feature: Feature) -> bool:
+ return all(feature in VERSION_TO_FEATURES[version] for version in target_versions)
+
+
+def find_pyproject_toml(path_search_start: str) -> Optional[str]:
+ """Find the absolute filepath to a pyproject.toml if it exists"""
+ path_project_root = find_project_root(path_search_start)
+ path_pyproject_toml = path_project_root / "pyproject.toml"
+ return str(path_pyproject_toml) if path_pyproject_toml.is_file() else None
+
+
+def parse_pyproject_toml(path_config: str) -> Dict[str, Any]:
+ """Parse a pyproject toml file, pulling out relevant parts for Black
+
+ If parsing fails, will raise a toml.TomlDecodeError
+ """
+ pyproject_toml = toml.load(path_config)
+ config = pyproject_toml.get("tool", {}).get("black", {})
+ return {k.replace("--", "").replace("-", "_"): v for k, v in config.items()}
+
+
+def read_pyproject_toml(
+ ctx: click.Context, param: click.Parameter, value: Union[str, int, bool, None]
+) -> Optional[str]:
+ """Inject Black configuration from "pyproject.toml" into defaults in `ctx`.
+ Returns the path to a successfully found and read configuration file, None
+ otherwise.
+ """
+ assert not isinstance(value, (int, bool)), "Invalid parameter type passed"
+ if not value:
+ value = find_pyproject_toml(ctx.params.get("src", ()))
+ if value is None:
+ return None
+
+ try:
+ config = parse_pyproject_toml(value)
+ except (toml.TomlDecodeError, OSError) as e:
+ raise click.FileError(
+ filename=value, hint=f"Error reading configuration file: {e}"
+ )
+
+ if not config:
+ return None
-class FileMode(Flag):
- AUTO_DETECT = 0
- PYTHON36 = 1
- PYI = 2
- NO_STRING_NORMALIZATION = 4
+ if ctx.default_map is None:
+ ctx.default_map = {}
+ ctx.default_map.update(config) # type: ignore # bad types in .pyi
+ return value
-@click.command()
+def target_version_option_callback(
+ c: click.Context, p: Union[click.Option, click.Parameter], v: Tuple[str, ...]
+) -> List[TargetVersion]:
+ """Compute the target versions from a --target-version flag.
+
+ This is its own function because mypy couldn't infer the type correctly
+ when it was a lambda, causing mypyc trouble.
+ """
+ return [TargetVersion[val.upper()] for val in v]
+
+
+@click.command(context_settings=dict(help_option_names=["-h", "--help"]))
+@click.option("-c", "--code", type=str, help="Format the code passed in as a string.")
@click.option(
"-l",
"--line-length",
type=int,
default=DEFAULT_LINE_LENGTH,
- help="How many character per line to allow.",
+ help="How many characters per line to allow.",
show_default=True,
)
+@click.option(
+ "-t",
+ "--target-version",
+ type=click.Choice([v.name.lower() for v in TargetVersion]),
+ callback=target_version_option_callback,
+ multiple=True,
+ help=(
+ "Python versions that should be supported by Black's output. [default: "
+ "per-file auto-detection]"
+ ),
+)
@click.option(
"--py36",
is_flag=True,
help=(
"Allow using Python 3.6-only syntax on all input files. This will put "
"trailing commas in function signatures and calls also after *args and "
- "**kwargs. [default: per-file auto-detection]"
+ "**kwargs. Deprecated; use --target-version instead. "
+ "[default: per-file auto-detection]"
),
)
@click.option(
"--quiet",
is_flag=True,
help=(
- "Don't emit non-error messages to stderr. Errors are still emitted, "
+ "Don't emit non-error messages to stderr. Errors are still emitted; "
"silence those with 2>/dev/null."
),
)
+@click.option(
+ "-v",
+ "--verbose",
+ is_flag=True,
+ help=(
+ "Also emit messages to stderr about files that were not changed or were "
+ "ignored due to --exclude=."
+ ),
+)
@click.version_option(version=__version__)
@click.argument(
"src",
type=click.Path(
exists=True, file_okay=True, dir_okay=True, readable=True, allow_dash=True
),
+ is_eager=True,
+)
+@click.option(
+ "--config",
+ type=click.Path(
+ exists=False, file_okay=True, dir_okay=False, readable=True, allow_dash=False
+ ),
+ is_eager=True,
+ callback=read_pyproject_toml,
+ help="Read configuration from PATH.",
)
@click.pass_context
def main(
ctx: click.Context,
+ code: Optional[str],
line_length: int,
+ target_version: List[TargetVersion],
check: bool,
diff: bool,
fast: bool,
py36: bool,
skip_string_normalization: bool,
quiet: bool,
+ verbose: bool,
include: str,
exclude: str,
- src: List[str],
+ src: Tuple[str, ...],
+ config: Optional[str],
) -> None:
"""The uncompromising code formatter."""
- sources: List[Path] = []
+ write_back = WriteBack.from_configuration(check=check, diff=diff)
+ if target_version:
+ if py36:
+ err("Cannot use both --target-version and --py36")
+ ctx.exit(2)
+ else:
+ versions = set(target_version)
+ elif py36:
+ err(
+ "--py36 is deprecated and will be removed in a future version. "
+ "Use --target-version py36 instead."
+ )
+ versions = PY36_VERSIONS
+ else:
+ # We'll autodetect later.
+ versions = set()
+ mode = Mode(
+ target_versions=versions,
+ line_length=line_length,
+ is_pyi=pyi,
+ string_normalization=not skip_string_normalization,
+ )
+ if config and verbose:
+ out(f"Using configuration from {config}.", bold=False, fg="blue")
+ if code is not None:
+ print(format_str(code, mode=mode))
+ ctx.exit(0)
try:
- include_regex = re.compile(include)
+ include_regex = re_compile_maybe_verbose(include)
except re.error:
err(f"Invalid regular expression for include given: {include!r}")
ctx.exit(2)
try:
- exclude_regex = re.compile(exclude)
+ exclude_regex = re_compile_maybe_verbose(exclude)
except re.error:
err(f"Invalid regular expression for exclude given: {exclude!r}")
ctx.exit(2)
+ report = Report(check=check, diff=diff, quiet=quiet, verbose=verbose)
root = find_project_root(src)
+ sources: Set[Path] = set()
+ path_empty(src, quiet, verbose, ctx)
for s in src:
p = Path(s)
if p.is_dir():
- sources.extend(
- gen_python_files_in_dir(p, root, include_regex, exclude_regex)
+ sources.update(
+ gen_python_files_in_dir(
+ p, root, include_regex, exclude_regex, report, get_gitignore(root)
+ )
)
elif p.is_file() or s == "-":
# if a file was explicitly given, we don't care about its extension
- sources.append(p)
+ sources.add(p)
else:
err(f"invalid path: {s}")
-
- if check and not diff:
- write_back = WriteBack.NO
- elif diff:
- write_back = WriteBack.DIFF
- else:
- write_back = WriteBack.YES
- mode = FileMode.AUTO_DETECT
- if py36:
- mode |= FileMode.PYTHON36
- if pyi:
- mode |= FileMode.PYI
- if skip_string_normalization:
- mode |= FileMode.NO_STRING_NORMALIZATION
- report = Report(check=check, quiet=quiet)
if len(sources) == 0:
- out("No paths given. Nothing to do 😴")
+ if verbose or not quiet:
+ out("No Python files are present to be formatted. Nothing to do 😴")
ctx.exit(0)
- return
- elif len(sources) == 1:
+ if len(sources) == 1:
reformat_one(
- src=sources[0],
- line_length=line_length,
+ src=sources.pop(),
fast=fast,
write_back=write_back,
mode=mode,
report=report,
)
else:
- loop = asyncio.get_event_loop()
- executor = ProcessPoolExecutor(max_workers=os.cpu_count())
- try:
- loop.run_until_complete(
- schedule_formatting(
- sources=sources,
- line_length=line_length,
- fast=fast,
- write_back=write_back,
- mode=mode,
- report=report,
- loop=loop,
- executor=executor,
- )
- )
- finally:
- shutdown(loop)
- if not quiet:
- out("All done! ✨ 🍰 ✨")
- click.echo(str(report))
+ reformat_many(
+ sources=sources, fast=fast, write_back=write_back, mode=mode, report=report
+ )
+
+ if verbose or not quiet:
+ out("Oh no! 💥 💔 💥" if report.return_code else "All done! ✨ 🍰 ✨")
+ click.secho(str(report), err=True)
ctx.exit(report.return_code)
+def path_empty(
+ src: Tuple[str, ...], quiet: bool, verbose: bool, ctx: click.Context
+) -> None:
+ """
+ Exit if there is no `src` provided for formatting
+ """
+ if not src:
+ if verbose or not quiet:
+ out("No Path provided. Nothing to do 😴")
+ ctx.exit(0)
+
+
def reformat_one(
- src: Path,
- line_length: int,
- fast: bool,
- write_back: WriteBack,
- mode: FileMode,
- report: "Report",
+ src: Path, fast: bool, write_back: WriteBack, mode: Mode, report: "Report"
) -> None:
"""Reformat a single file under `src` without spawning child processes.
- If `quiet` is True, non-error messages are not output. `line_length`,
- `write_back`, `fast` and `pyi` options are passed to
+ `fast`, `write_back`, and `mode` options are passed to
:func:`format_file_in_place` or :func:`format_stdin_to_stdout`.
"""
try:
changed = Changed.NO
if not src.is_file() and str(src) == "-":
- if format_stdin_to_stdout(
- line_length=line_length, fast=fast, write_back=write_back, mode=mode
- ):
+ if format_stdin_to_stdout(fast=fast, write_back=write_back, mode=mode):
changed = Changed.YES
else:
cache: Cache = {}
if write_back != WriteBack.DIFF:
- cache = read_cache(line_length, mode)
+ cache = read_cache(mode)
res_src = src.resolve()
if res_src in cache and cache[res_src] == get_cache_info(res_src):
changed = Changed.CACHED
if changed is not Changed.CACHED and format_file_in_place(
- src,
- line_length=line_length,
- fast=fast,
- write_back=write_back,
- mode=mode,
+ src, fast=fast, write_back=write_back, mode=mode
):
changed = Changed.YES
- if write_back == WriteBack.YES and changed is not Changed.NO:
- write_cache(cache, [src], line_length, mode)
+ if (write_back is WriteBack.YES and changed is not Changed.CACHED) or (
+ write_back is WriteBack.CHECK and changed is Changed.NO
+ ):
+ write_cache(cache, [src], mode)
report.done(src, changed)
except Exception as exc:
report.failed(src, str(exc))
+def reformat_many(
+ sources: Set[Path], fast: bool, write_back: WriteBack, mode: Mode, report: "Report"
+) -> None:
+ """Reformat multiple files using a ProcessPoolExecutor."""
+ loop = asyncio.get_event_loop()
+ worker_count = os.cpu_count()
+ if sys.platform == "win32":
+ # Work around https://bugs.python.org/issue26903
+ worker_count = min(worker_count, 61)
+ executor = ProcessPoolExecutor(max_workers=worker_count)
+ try:
+ loop.run_until_complete(
+ schedule_formatting(
+ sources=sources,
+ fast=fast,
+ write_back=write_back,
+ mode=mode,
+ report=report,
+ loop=loop,
+ executor=executor,
+ )
+ )
+ finally:
+ shutdown(loop)
+ executor.shutdown()
+
+
async def schedule_formatting(
- sources: List[Path],
- line_length: int,
+ sources: Set[Path],
fast: bool,
write_back: WriteBack,
- mode: FileMode,
+ mode: Mode,
report: "Report",
- loop: BaseEventLoop,
+ loop: asyncio.AbstractEventLoop,
executor: Executor,
) -> None:
"""Run formatting of `sources` in parallel using the provided `executor`.
(Use ProcessPoolExecutors for actual parallelism.)
- `line_length`, `write_back`, `fast`, and `pyi` options are passed to
+ `write_back`, `fast`, and `mode` options are passed to
:func:`format_file_in_place`.
"""
cache: Cache = {}
if write_back != WriteBack.DIFF:
- cache = read_cache(line_length, mode)
+ cache = read_cache(mode)
sources, cached = filter_cached(cache, sources)
- for src in cached:
+ for src in sorted(cached):
report.done(src, Changed.CACHED)
+ if not sources:
+ return
+
cancelled = []
- formatted = []
- if sources:
- lock = None
- if write_back == WriteBack.DIFF:
- # For diff output, we need locks to ensure we don't interleave output
- # from different processes.
- manager = Manager()
- lock = manager.Lock()
- tasks = {
+ sources_to_cache = []
+ lock = None
+ if write_back == WriteBack.DIFF:
+ # For diff output, we need locks to ensure we don't interleave output
+ # from different processes.
+ manager = Manager()
+ lock = manager.Lock()
+ tasks = {
+ asyncio.ensure_future(
loop.run_in_executor(
- executor,
- format_file_in_place,
- src,
- line_length,
- fast,
- write_back,
- mode,
- lock,
- ): src
- for src in sorted(sources)
- }
- pending: Iterable[asyncio.Task] = tasks.keys()
- try:
- loop.add_signal_handler(signal.SIGINT, cancel, pending)
- loop.add_signal_handler(signal.SIGTERM, cancel, pending)
- except NotImplementedError:
- # There are no good alternatives for these on Windows
- pass
- while pending:
- done, _ = await asyncio.wait(pending, return_when=asyncio.FIRST_COMPLETED)
- for task in done:
- src = tasks.pop(task)
- if task.cancelled():
- cancelled.append(task)
- elif task.exception():
- report.failed(src, str(task.exception()))
- else:
- formatted.append(src)
- report.done(src, Changed.YES if task.result() else Changed.NO)
+ executor, format_file_in_place, src, fast, mode, write_back, lock
+ )
+ ): src
+ for src in sorted(sources)
+ }
+ pending: Iterable["asyncio.Future[bool]"] = tasks.keys()
+ try:
+ loop.add_signal_handler(signal.SIGINT, cancel, pending)
+ loop.add_signal_handler(signal.SIGTERM, cancel, pending)
+ except NotImplementedError:
+ # There are no good alternatives for these on Windows.
+ pass
+ while pending:
+ done, _ = await asyncio.wait(pending, return_when=asyncio.FIRST_COMPLETED)
+ for task in done:
+ src = tasks.pop(task)
+ if task.cancelled():
+ cancelled.append(task)
+ elif task.exception():
+ report.failed(src, str(task.exception()))
+ else:
+ changed = Changed.YES if task.result() else Changed.NO
+ # If the file was written back or was successfully checked as
+ # well-formatted, store this information in the cache.
+ if write_back is WriteBack.YES or (
+ write_back is WriteBack.CHECK and changed is Changed.NO
+ ):
+ sources_to_cache.append(src)
+ report.done(src, changed)
if cancelled:
await asyncio.gather(*cancelled, loop=loop, return_exceptions=True)
- if write_back == WriteBack.YES and formatted:
- write_cache(cache, formatted, line_length, mode)
+ if sources_to_cache:
+ write_cache(cache, sources_to_cache, mode)
def format_file_in_place(
src: Path,
- line_length: int,
fast: bool,
+ mode: Mode,
write_back: WriteBack = WriteBack.NO,
- mode: FileMode = FileMode.AUTO_DETECT,
lock: Any = None, # multiprocessing.Manager().Lock() is some crazy proxy
) -> bool:
"""Format file under `src` path. Return True if changed.
- If `write_back` is True, write reformatted code back to stdout.
- `line_length` and `fast` options are passed to :func:`format_file_contents`.
+ If `write_back` is DIFF, write a diff to stdout. If it is YES, write reformatted
+ code to the file.
+ `mode` and `fast` options are passed to :func:`format_file_contents`.
"""
if src.suffix == ".pyi":
- mode |= FileMode.PYI
- with tokenize.open(src) as src_buffer:
- src_contents = src_buffer.read()
+ mode = replace(mode, is_pyi=True)
+
+ then = datetime.utcfromtimestamp(src.stat().st_mtime)
+ with open(src, "rb") as buf:
+ src_contents, encoding, newline = decode_bytes(buf.read())
try:
- dst_contents = format_file_contents(
- src_contents, line_length=line_length, fast=fast, mode=mode
- )
+ dst_contents = format_file_contents(src_contents, fast=fast, mode=mode)
except NothingChanged:
return False
- if write_back == write_back.YES:
- with open(src, "w", encoding=src_buffer.encoding) as f:
+ if write_back == WriteBack.YES:
+ with open(src, "w", encoding=encoding, newline=newline) as f:
f.write(dst_contents)
- elif write_back == write_back.DIFF:
- src_name = f"{src} (original)"
- dst_name = f"{src} (formatted)"
+ elif write_back == WriteBack.DIFF:
+ now = datetime.utcnow()
+ src_name = f"{src}\t{then} +0000"
+ dst_name = f"{src}\t{now} +0000"
diff_contents = diff(src_contents, dst_contents, src_name, dst_name)
- if lock:
- lock.acquire()
- try:
- sys.stdout.write(diff_contents)
- finally:
- if lock:
- lock.release()
+
+ with lock or nullcontext():
+ f = io.TextIOWrapper(
+ sys.stdout.buffer,
+ encoding=encoding,
+ newline=newline,
+ write_through=True,
+ )
+ f.write(diff_contents)
+ f.detach()
+
return True
def format_stdin_to_stdout(
- line_length: int,
- fast: bool,
- write_back: WriteBack = WriteBack.NO,
- mode: FileMode = FileMode.AUTO_DETECT,
+ fast: bool, *, write_back: WriteBack = WriteBack.NO, mode: Mode
) -> bool:
"""Format file on stdin. Return True if changed.
- If `write_back` is True, write reformatted code back to stdout.
- `line_length`, `fast`, `is_pyi`, and `force_py36` arguments are passed to
+ If `write_back` is YES, write reformatted code back to stdout. If it is DIFF,
+ write a diff to stdout. The `mode` argument is passed to
:func:`format_file_contents`.
"""
- src = sys.stdin.read()
+ then = datetime.utcnow()
+ src, encoding, newline = decode_bytes(sys.stdin.buffer.read())
dst = src
try:
- dst = format_file_contents(src, line_length=line_length, fast=fast, mode=mode)
+ dst = format_file_contents(src, fast=fast, mode=mode)
return True
except NothingChanged:
return False
finally:
+ f = io.TextIOWrapper(
+ sys.stdout.buffer, encoding=encoding, newline=newline, write_through=True
+ )
if write_back == WriteBack.YES:
- sys.stdout.write(dst)
+ f.write(dst)
elif write_back == WriteBack.DIFF:
- src_name = "<stdin> (original)"
- dst_name = "<stdin> (formatted)"
- sys.stdout.write(diff(src, dst, src_name, dst_name))
+ now = datetime.utcnow()
+ src_name = f"STDIN\t{then} +0000"
+ dst_name = f"STDOUT\t{now} +0000"
+ f.write(diff(src, dst, src_name, dst_name))
+ f.detach()
-def format_file_contents(
- src_contents: str,
- *,
- line_length: int,
- fast: bool,
- mode: FileMode = FileMode.AUTO_DETECT,
-) -> FileContent:
+def format_file_contents(src_contents: str, *, fast: bool, mode: Mode) -> FileContent:
"""Reformat contents a file and return new contents.
If `fast` is False, additionally confirm that the reformatted code is
valid by calling :func:`assert_equivalent` and :func:`assert_stable` on it.
- `line_length` is passed to :func:`format_str`.
+ `mode` is passed to :func:`format_str`.
"""
if src_contents.strip() == "":
raise NothingChanged
- dst_contents = format_str(src_contents, line_length=line_length, mode=mode)
+ dst_contents = format_str(src_contents, mode=mode)
if src_contents == dst_contents:
raise NothingChanged
if not fast:
assert_equivalent(src_contents, dst_contents)
- assert_stable(src_contents, dst_contents, line_length=line_length, mode=mode)
+ assert_stable(src_contents, dst_contents, mode=mode)
return dst_contents
-def format_str(
- src_contents: str, line_length: int, *, mode: FileMode = FileMode.AUTO_DETECT
-) -> FileContent:
+def format_str(src_contents: str, *, mode: Mode) -> FileContent:
"""Reformat a string and return new contents.
- `line_length` determines how many characters per line are allowed.
+ `mode` determines formatting options, such as how many characters per line are
+ allowed. Example:
+
+ >>> import black
+ >>> print(black.format_str("def f(arg:str='')->None:...", mode=Mode()))
+ def f(arg: str = "") -> None:
+ ...
+
+ A more complex example:
+ >>> print(
+ ... black.format_str(
+ ... "def f(arg:str='')->None: hey",
+ ... mode=black.Mode(
+ ... target_versions={black.TargetVersion.PY36},
+ ... line_length=10,
+ ... string_normalization=False,
+ ... is_pyi=False,
+ ... ),
+ ... ),
+ ... )
+ def f(
+ arg: str = '',
+ ) -> None:
+ hey
+
"""
- src_node = lib2to3_parse(src_contents)
- dst_contents = ""
+ src_node = lib2to3_parse(src_contents.lstrip(), mode.target_versions)
+ dst_contents = []
future_imports = get_future_imports(src_node)
- is_pyi = bool(mode & FileMode.PYI)
- py36 = bool(mode & FileMode.PYTHON36) or is_python36(src_node)
- normalize_strings = not bool(mode & FileMode.NO_STRING_NORMALIZATION)
+ if mode.target_versions:
+ versions = mode.target_versions
+ else:
+ versions = detect_target_versions(src_node)
+ normalize_fmt_off(src_node)
lines = LineGenerator(
- remove_u_prefix=py36 or "unicode_literals" in future_imports,
- is_pyi=is_pyi,
- normalize_strings=normalize_strings,
+ remove_u_prefix="unicode_literals" in future_imports
+ or supports_feature(versions, Feature.UNICODE_LITERALS),
+ is_pyi=mode.is_pyi,
+ normalize_strings=mode.string_normalization,
)
- elt = EmptyLineTracker(is_pyi=is_pyi)
+ elt = EmptyLineTracker(is_pyi=mode.is_pyi)
empty_line = Line()
after = 0
+ split_line_features = {
+ feature
+ for feature in {Feature.TRAILING_COMMA_IN_CALL, Feature.TRAILING_COMMA_IN_DEF}
+ if supports_feature(versions, feature)
+ }
for current_line in lines.visit(src_node):
- for _ in range(after):
- dst_contents += str(empty_line)
+ dst_contents.append(str(empty_line) * after)
before, after = elt.maybe_empty_lines(current_line)
- for _ in range(before):
- dst_contents += str(empty_line)
- for line in split_line(current_line, line_length=line_length, py36=py36):
- dst_contents += str(line)
- return dst_contents
+ dst_contents.append(str(empty_line) * before)
+ for line in split_line(
+ current_line, line_length=mode.line_length, features=split_line_features
+ ):
+ dst_contents.append(str(line))
+ return "".join(dst_contents)
+
+
+def decode_bytes(src: bytes) -> Tuple[FileContent, Encoding, NewLine]:
+ """Return a tuple of (decoded_contents, encoding, newline).
+ `newline` is either CRLF or LF but `decoded_contents` is decoded with
+ universal newlines (i.e. only contains LF).
+ """
+ srcbuf = io.BytesIO(src)
+ encoding, lines = tokenize.detect_encoding(srcbuf.readline)
+ if not lines:
+ return "", encoding, "\n"
+
+ newline = "\r\n" if b"\r\n" == lines[0][-2:] else "\n"
+ srcbuf.seek(0)
+ with io.TextIOWrapper(srcbuf, encoding) as tiow:
+ return tiow.read(), encoding, newline
+
+
+def get_grammars(target_versions: Set[TargetVersion]) -> List[Grammar]:
+ if not target_versions:
+ # No target_version specified, so try all grammars.
+ return [
+ # Python 3.7+
+ pygram.python_grammar_no_print_statement_no_exec_statement_async_keywords,
+ # Python 3.0-3.6
+ pygram.python_grammar_no_print_statement_no_exec_statement,
+ # Python 2.7 with future print_function import
+ pygram.python_grammar_no_print_statement,
+ # Python 2.7
+ pygram.python_grammar,
+ ]
-GRAMMARS = [
- pygram.python_grammar_no_print_statement_no_exec_statement,
- pygram.python_grammar_no_print_statement,
- pygram.python_grammar,
-]
+ if all(version.is_python2() for version in target_versions):
+ # Python 2-only code, so try Python 2 grammars.
+ return [
+ # Python 2.7 with future print_function import
+ pygram.python_grammar_no_print_statement,
+ # Python 2.7
+ pygram.python_grammar,
+ ]
+
+ # Python 3-compatible code, so only try Python 3 grammar.
+ grammars = []
+ # If we have to parse both, try to parse async as a keyword first
+ if not supports_feature(target_versions, Feature.ASYNC_IDENTIFIERS):
+ # Python 3.7+
+ grammars.append(
+ pygram.python_grammar_no_print_statement_no_exec_statement_async_keywords
+ )
+ if not supports_feature(target_versions, Feature.ASYNC_KEYWORDS):
+ # Python 3.0-3.6
+ grammars.append(pygram.python_grammar_no_print_statement_no_exec_statement)
+ # At least one of the above branches must have been taken, because every Python
+ # version has exactly one of the two 'ASYNC_*' flags
+ return grammars
-def lib2to3_parse(src_txt: str) -> Node:
+def lib2to3_parse(src_txt: str, target_versions: Iterable[TargetVersion] = ()) -> Node:
"""Given a string with source, return the lib2to3 Node."""
- grammar = pygram.python_grammar_no_print_statement
- if src_txt[-1] != "\n":
- nl = "\r\n" if "\r\n" in src_txt[:1024] else "\n"
- src_txt += nl
- for grammar in GRAMMARS:
+ if src_txt[-1:] != "\n":
+ src_txt += "\n"
+
+ for grammar in get_grammars(set(target_versions)):
drv = driver.Driver(grammar, pytree.convert)
try:
result = drv.parse_string(src_txt, True)
faulty_line = lines[lineno - 1]
except IndexError:
faulty_line = "<line number missing in source>"
- exc = ValueError(f"Cannot parse: {lineno}:{column}: {faulty_line}")
+ exc = InvalidInput(f"Cannot parse: {lineno}:{column}: {faulty_line}")
else:
raise exc from None
if node.type < 256:
name = token.tok_name[node.type]
else:
- name = type_repr(node.type)
- yield from getattr(self, f"visit_{name}", self.visit_default)(node)
+ name = str(type_repr(node.type))
+ # We explicitly branch on whether a visitor exists (instead of
+ # using self.visit_default as the default arg to getattr) in order
+ # to save needing to create a bound method object and so mypyc can
+ # generate a native call to visit_default.
+ visitf = getattr(self, f"visit_{name}", None)
+ if visitf:
+ yield from visitf(node)
+ else:
+ yield from self.visit_default(node)
def visit_default(self, node: LN) -> Iterator[T]:
"""Default `visit_*()` implementation. Recurses to children of `node`."""
out(f" {node.value!r}", fg="blue", bold=False)
@classmethod
- def show(cls, code: str) -> None:
+ def show(cls, code: Union[str, Leaf, Node]) -> None:
"""Pretty-print the lib2to3 AST of a given string of `code`.
Convenience method for debugging.
"""
v: DebugVisitor[None] = DebugVisitor()
- list(v.visit(lib2to3_parse(code)))
+ if isinstance(code, str):
+ code = lib2to3_parse(code)
+ list(v.visit(code))
-KEYWORDS = set(keyword.kwlist)
-WHITESPACE = {token.DEDENT, token.INDENT, token.NEWLINE}
-FLOW_CONTROL = {"return", "raise", "break", "continue"}
-STATEMENT = {
+WHITESPACE: Final = {token.DEDENT, token.INDENT, token.NEWLINE}
+STATEMENT: Final = {
syms.if_stmt,
syms.while_stmt,
syms.for_stmt,
syms.funcdef,
syms.classdef,
}
-STANDALONE_COMMENT = 153
-LOGIC_OPERATORS = {"and", "or"}
-COMPARATORS = {
+STANDALONE_COMMENT: Final = 153
+token.tok_name[STANDALONE_COMMENT] = "STANDALONE_COMMENT"
+LOGIC_OPERATORS: Final = {"and", "or"}
+COMPARATORS: Final = {
token.LESS,
token.GREATER,
token.EQEQUAL,
token.LESSEQUAL,
token.GREATEREQUAL,
}
-MATH_OPERATORS = {
+MATH_OPERATORS: Final = {
token.VBAR,
token.CIRCUMFLEX,
token.AMPER,
token.TILDE,
token.DOUBLESTAR,
}
-STARS = {token.STAR, token.DOUBLESTAR}
-VARARGS_PARENTS = {
+STARS: Final = {token.STAR, token.DOUBLESTAR}
+VARARGS_SPECIALS: Final = STARS | {token.SLASH}
+VARARGS_PARENTS: Final = {
syms.arglist,
syms.argument, # double star in arglist
syms.trailer, # single argument to call
syms.typedargslist,
syms.varargslist, # lambdas
}
-UNPACKING_PARENTS = {
+UNPACKING_PARENTS: Final = {
syms.atom, # single element of a list or set literal
syms.dictsetmaker,
syms.listmaker,
syms.testlist_gexp,
+ syms.testlist_star_expr,
}
-TEST_DESCENDANTS = {
+TEST_DESCENDANTS: Final = {
syms.test,
syms.lambdef,
syms.or_test,
syms.term,
syms.power,
}
-ASSIGNMENTS = {
+ASSIGNMENTS: Final = {
"=",
"+=",
"-=",
"**=",
"//=",
}
-COMPREHENSION_PRIORITY = 20
-COMMA_PRIORITY = 18
-TERNARY_PRIORITY = 16
-LOGIC_PRIORITY = 14
-STRING_PRIORITY = 12
-COMPARATOR_PRIORITY = 10
-MATH_PRIORITIES = {
+COMPREHENSION_PRIORITY: Final = 20
+COMMA_PRIORITY: Final = 18
+TERNARY_PRIORITY: Final = 16
+LOGIC_PRIORITY: Final = 14
+STRING_PRIORITY: Final = 12
+COMPARATOR_PRIORITY: Final = 10
+MATH_PRIORITIES: Final = {
token.VBAR: 9,
token.CIRCUMFLEX: 8,
token.AMPER: 7,
token.TILDE: 3,
token.DOUBLESTAR: 2,
}
-DOT_PRIORITY = 1
+DOT_PRIORITY: Final = 1
@dataclass
"""Keeps track of brackets on a line."""
depth: int = 0
- bracket_match: Dict[Tuple[Depth, NodeType], Leaf] = Factory(dict)
- delimiters: Dict[LeafID, Priority] = Factory(dict)
+ bracket_match: Dict[Tuple[Depth, NodeType], Leaf] = field(default_factory=dict)
+ delimiters: Dict[LeafID, Priority] = field(default_factory=dict)
previous: Optional[Leaf] = None
- _for_loop_variable: int = 0
- _lambda_arguments: int = 0
+ _for_loop_depths: List[int] = field(default_factory=list)
+ _lambda_argument_depths: List[int] = field(default_factory=list)
def mark(self, leaf: Leaf) -> None:
"""Mark `leaf` with bracket-related metadata. Keep track of delimiters.
"""Return True if there is an yet unmatched open bracket on the line."""
return bool(self.bracket_match)
- def max_delimiter_priority(self, exclude: Iterable[LeafID] = ()) -> int:
+ def max_delimiter_priority(self, exclude: Iterable[LeafID] = ()) -> Priority:
"""Return the highest priority of a delimiter found on the line.
Values are consistent with what `is_split_*_delimiter()` return.
"""
return max(v for k, v in self.delimiters.items() if k not in exclude)
- def delimiter_count_with_priority(self, priority: int = 0) -> int:
+ def delimiter_count_with_priority(self, priority: Priority = 0) -> int:
"""Return the number of delimiters with the given `priority`.
If no `priority` is passed, defaults to max priority on the line.
"""
if leaf.type == token.NAME and leaf.value == "for":
self.depth += 1
- self._for_loop_variable += 1
+ self._for_loop_depths.append(self.depth)
return True
return False
def maybe_decrement_after_for_loop_variable(self, leaf: Leaf) -> bool:
"""See `maybe_increment_for_loop_variable` above for explanation."""
- if self._for_loop_variable and leaf.type == token.NAME and leaf.value == "in":
+ if (
+ self._for_loop_depths
+ and self._for_loop_depths[-1] == self.depth
+ and leaf.type == token.NAME
+ and leaf.value == "in"
+ ):
self.depth -= 1
- self._for_loop_variable -= 1
+ self._for_loop_depths.pop()
return True
return False
"""
if leaf.type == token.NAME and leaf.value == "lambda":
self.depth += 1
- self._lambda_arguments += 1
+ self._lambda_argument_depths.append(self.depth)
return True
return False
def maybe_decrement_after_lambda_arguments(self, leaf: Leaf) -> bool:
"""See `maybe_increment_lambda_arguments` above for explanation."""
- if self._lambda_arguments and leaf.type == token.COLON:
+ if (
+ self._lambda_argument_depths
+ and self._lambda_argument_depths[-1] == self.depth
+ and leaf.type == token.COLON
+ ):
self.depth -= 1
- self._lambda_arguments -= 1
+ self._lambda_argument_depths.pop()
return True
return False
"""Holds leaves and comments. Can be printed with `str(line)`."""
depth: int = 0
- leaves: List[Leaf] = Factory(list)
- comments: List[Tuple[Index, Leaf]] = Factory(list)
- bracket_tracker: BracketTracker = Factory(BracketTracker)
+ leaves: List[Leaf] = field(default_factory=list)
+ # keys ordered like `leaves`
+ comments: Dict[LeafID, List[Leaf]] = field(default_factory=dict)
+ bracket_tracker: BracketTracker = field(default_factory=BracketTracker)
inside_brackets: bool = False
should_explode: bool = False
Leaf(token.DOT, ".") for _ in range(3)
]
+ @property
+ def is_collection_with_optional_trailing_comma(self) -> bool:
+ """Is this line a collection literal with a trailing comma that's optional?
+
+ Note that the trailing comma in a 1-tuple is not optional.
+ """
+ if not self.leaves or len(self.leaves) < 4:
+ return False
+
+ # Look for and address a trailing colon.
+ if self.leaves[-1].type == token.COLON:
+ closer = self.leaves[-2]
+ close_index = -2
+ else:
+ closer = self.leaves[-1]
+ close_index = -1
+ if closer.type not in CLOSING_BRACKETS or self.inside_brackets:
+ return False
+
+ if closer.type == token.RPAR:
+ # Tuples require an extra check, because if there's only
+ # one element in the tuple removing the comma unmakes the
+ # tuple.
+ #
+ # We also check for parens before looking for the trailing
+ # comma because in some cases (eg assigning a dict
+ # literal) the literal gets wrapped in temporary parens
+ # during parsing. This case is covered by the
+ # collections.py test data.
+ opener = closer.opening_bracket
+ for _open_index, leaf in enumerate(self.leaves):
+ if leaf is opener:
+ break
+
+ else:
+ # Couldn't find the matching opening paren, play it safe.
+ return False
+
+ commas = 0
+ comma_depth = self.leaves[close_index - 1].bracket_depth
+ for leaf in self.leaves[_open_index + 1 : close_index]:
+ if leaf.bracket_depth == comma_depth and leaf.type == token.COMMA:
+ commas += 1
+ if commas > 1:
+ # We haven't looked yet for the trailing comma because
+ # we might also have caught noop parens.
+ return self.leaves[close_index - 1].type == token.COMMA
+
+ elif commas == 1:
+ return False # it's either a one-tuple or didn't have a trailing comma
+
+ if self.leaves[close_index - 1].type in CLOSING_BRACKETS:
+ close_index -= 1
+ closer = self.leaves[close_index]
+ if closer.type == token.RPAR:
+ # TODO: this is a gut feeling. Will we ever see this?
+ return False
+
+ if self.leaves[close_index - 1].type != token.COMMA:
+ return False
+
+ return True
+
@property
def is_def(self) -> bool:
"""Is this a function definition? (Also returns True for async defs.)"""
def contains_standalone_comments(self, depth_limit: int = sys.maxsize) -> bool:
"""If so, needs to be split before emitting."""
for leaf in self.leaves:
- if leaf.type == STANDALONE_COMMENT:
- if leaf.bracket_depth <= depth_limit:
- return True
+ if leaf.type == STANDALONE_COMMENT and leaf.bracket_depth <= depth_limit:
+ return True
return False
- def maybe_remove_trailing_comma(self, closing: Leaf) -> bool:
- """Remove trailing comma if there is one and it's safe."""
- if not (
- self.leaves
- and self.leaves[-1].type == token.COMMA
- and closing.type in CLOSING_BRACKETS
- ):
+ def contains_uncollapsable_type_comments(self) -> bool:
+ ignored_ids = set()
+ try:
+ last_leaf = self.leaves[-1]
+ ignored_ids.add(id(last_leaf))
+ if last_leaf.type == token.COMMA or (
+ last_leaf.type == token.RPAR and not last_leaf.value
+ ):
+ # When trailing commas or optional parens are inserted by Black for
+ # consistency, comments after the previous last element are not moved
+ # (they don't have to, rendering will still be correct). So we ignore
+ # trailing commas and invisible.
+ last_leaf = self.leaves[-2]
+ ignored_ids.add(id(last_leaf))
+ except IndexError:
return False
- if closing.type == token.RBRACE:
- self.remove_trailing_comma()
- return True
+ # A type comment is uncollapsable if it is attached to a leaf
+ # that isn't at the end of the line (since that could cause it
+ # to get associated to a different argument) or if there are
+ # comments before it (since that could cause it to get hidden
+ # behind a comment.
+ comment_seen = False
+ for leaf_id, comments in self.comments.items():
+ for comment in comments:
+ if is_type_comment(comment):
+ if comment_seen or (
+ not is_type_comment(comment, " ignore")
+ and leaf_id not in ignored_ids
+ ):
+ return True
+
+ comment_seen = True
- if closing.type == token.RSQB:
- comma = self.leaves[-1]
- if comma.parent and comma.parent.type == syms.listmaker:
- self.remove_trailing_comma()
- return True
+ return False
- # For parens let's check if it's safe to remove the comma.
- # Imports are always safe.
- if self.is_import:
- self.remove_trailing_comma()
- return True
+ def contains_unsplittable_type_ignore(self) -> bool:
+ if not self.leaves:
+ return False
- # Otheriwsse, if the trailing one is the only one, we might mistakenly
- # change a tuple into a different type by removing the comma.
- depth = closing.bracket_depth + 1
- commas = 0
- opening = closing.opening_bracket
- for _opening_index, leaf in enumerate(self.leaves):
- if leaf is opening:
- break
+ # If a 'type: ignore' is attached to the end of a line, we
+ # can't split the line, because we can't know which of the
+ # subexpressions the ignore was meant to apply to.
+ #
+ # We only want this to apply to actual physical lines from the
+ # original source, though: we don't want the presence of a
+ # 'type: ignore' at the end of a multiline expression to
+ # justify pushing it all onto one line. Thus we
+ # (unfortunately) need to check the actual source lines and
+ # only report an unsplittable 'type: ignore' if this line was
+ # one line in the original code.
+
+ # Grab the first and last line numbers, skipping generated leaves
+ first_line = next((l.lineno for l in self.leaves if l.lineno != 0), 0)
+ last_line = next((l.lineno for l in reversed(self.leaves) if l.lineno != 0), 0)
+
+ if first_line == last_line:
+ # We look at the last two leaves since a comma or an
+ # invisible paren could have been added at the end of the
+ # line.
+ for node in self.leaves[-2:]:
+ for comment in self.comments.get(id(node), []):
+ if is_type_comment(comment, " ignore"):
+ return True
- else:
- return False
+ return False
- for leaf in self.leaves[_opening_index + 1 :]:
- if leaf is closing:
- break
+ def contains_multiline_strings(self) -> bool:
+ return any(is_multiline_string(leaf) for leaf in self.leaves)
- bracket_depth = leaf.bracket_depth
- if bracket_depth == depth and leaf.type == token.COMMA:
- commas += 1
- if leaf.parent and leaf.parent.type == syms.arglist:
- commas += 1
- break
+ def maybe_remove_trailing_comma(self, closing: Leaf) -> bool:
+ """Remove trailing comma if there is one and it's safe."""
+ if not (self.leaves and self.leaves[-1].type == token.COMMA):
+ return False
- if commas > 1:
- self.remove_trailing_comma()
- return True
+ # We remove trailing commas only in the case of importing a
+ # single name from a module.
+ if not (
+ self.leaves
+ and self.is_import
+ and len(self.leaves) > 4
+ and self.leaves[-1].type == token.COMMA
+ and closing.type in CLOSING_BRACKETS
+ and self.leaves[-4].type == token.NAME
+ and (
+ # regular `from foo import bar,`
+ self.leaves[-4].value == "import"
+ # `from foo import (bar as baz,)
+ or (
+ len(self.leaves) > 6
+ and self.leaves[-6].value == "import"
+ and self.leaves[-3].value == "as"
+ )
+ # `from foo import bar as baz,`
+ or (
+ len(self.leaves) > 5
+ and self.leaves[-5].value == "import"
+ and self.leaves[-3].value == "as"
+ )
+ )
+ and closing.type == token.RPAR
+ ):
+ return False
- return False
+ self.remove_trailing_comma()
+ return True
def append_comment(self, comment: Leaf) -> bool:
"""Add an inline or standalone comment to the line."""
if comment.type != token.COMMENT:
return False
- after = len(self.leaves) - 1
- if after == -1:
+ if not self.leaves:
comment.type = STANDALONE_COMMENT
comment.prefix = ""
return False
- else:
- self.comments.append((after, comment))
- return True
-
- def comments_after(self, leaf: Leaf, _index: int = -1) -> Iterator[Leaf]:
- """Generate comments that should appear directly after `leaf`.
-
- Provide a non-negative leaf `_index` to speed up the function.
- """
- if _index == -1:
- for _index, _leaf in enumerate(self.leaves):
- if leaf is _leaf:
- break
-
- else:
- return
+ last_leaf = self.leaves[-1]
+ if (
+ last_leaf.type == token.RPAR
+ and not last_leaf.value
+ and last_leaf.parent
+ and len(list(last_leaf.parent.leaves())) <= 3
+ and not is_type_comment(comment)
+ ):
+ # Comments on an optional parens wrapping a single leaf should belong to
+ # the wrapped node except if it's a type comment. Pinning the comment like
+ # this avoids unstable formatting caused by comment migration.
+ if len(self.leaves) < 2:
+ comment.type = STANDALONE_COMMENT
+ comment.prefix = ""
+ return False
+
+ last_leaf = self.leaves[-2]
+ self.comments.setdefault(id(last_leaf), []).append(comment)
+ return True
- for index, comment_after in self.comments:
- if _index == index:
- yield comment_after
+ def comments_after(self, leaf: Leaf) -> List[Leaf]:
+ """Generate comments that should appear directly after `leaf`."""
+ return self.comments.get(id(leaf), [])
def remove_trailing_comma(self) -> None:
"""Remove the trailing comma and moves the comments attached to it."""
- comma_index = len(self.leaves) - 1
- for i in range(len(self.comments)):
- comment_index, comment = self.comments[i]
- if comment_index == comma_index:
- self.comments[i] = (comma_index - 1, comment)
- self.leaves.pop()
+ trailing_comma = self.leaves.pop()
+ trailing_comma_comments = self.comments.pop(id(trailing_comma), [])
+ self.comments.setdefault(id(self.leaves[-1]), []).extend(
+ trailing_comma_comments
+ )
def is_complex_subscript(self, leaf: Leaf) -> bool:
"""Return True iff `leaf` is part of a slice with non-trivial exprs."""
- open_lsqb = (
- leaf if leaf.type == token.LSQB else self.bracket_tracker.get_open_lsqb()
- )
+ open_lsqb = self.bracket_tracker.get_open_lsqb()
if open_lsqb is None:
return False
subscript_start = open_lsqb.next_sibling
- if (
- isinstance(subscript_start, Node)
- and subscript_start.type == syms.subscriptlist
- ):
- subscript_start = child_towards(subscript_start, leaf)
+
+ if isinstance(subscript_start, Node):
+ if subscript_start.type == syms.listmaker:
+ return False
+
+ if subscript_start.type == syms.subscriptlist:
+ subscript_start = child_towards(subscript_start, leaf)
return subscript_start is not None and any(
n.type in TEST_DESCENDANTS for n in subscript_start.pre_order()
)
res = f"{first.prefix}{indent}{first.value}"
for leaf in leaves:
res += str(leaf)
- for _, comment in self.comments:
+ for comment in itertools.chain.from_iterable(self.comments.values()):
res += str(comment)
return res + "\n"
return bool(self.leaves or self.comments)
-class UnformattedLines(Line):
- """Just like :class:`Line` but stores lines which aren't reformatted."""
-
- def append(self, leaf: Leaf, preformatted: bool = True) -> None:
- """Just add a new `leaf` to the end of the lines.
-
- The `preformatted` argument is ignored.
-
- Keeps track of indentation `depth`, which is useful when the user
- says `# fmt: on`. Otherwise, doesn't do anything with the `leaf`.
- """
- try:
- list(generate_comments(leaf))
- except FormatOn as f_on:
- self.leaves.append(f_on.leaf_from_consumed(leaf))
- raise
-
- self.leaves.append(leaf)
- if leaf.type == token.INDENT:
- self.depth += 1
- elif leaf.type == token.DEDENT:
- self.depth -= 1
-
- def __str__(self) -> str:
- """Render unformatted lines from leaves which were added with `append()`.
-
- `depth` is not used for indentation in this case.
- """
- if not self:
- return "\n"
-
- res = ""
- for leaf in self.leaves:
- res += str(leaf)
- return res
-
- def append_comment(self, comment: Leaf) -> bool:
- """Not implemented in this class. Raises `NotImplementedError`."""
- raise NotImplementedError("Unformatted lines don't store comments separately.")
-
- def maybe_remove_trailing_comma(self, closing: Leaf) -> bool:
- """Does nothing and returns False."""
- return False
-
- def maybe_increment_for_loop_variable(self, leaf: Leaf) -> bool:
- """Does nothing and returns False."""
- return False
-
-
@dataclass
class EmptyLineTracker:
"""Provides a stateful method that returns the number of potential extra
is_pyi: bool = False
previous_line: Optional[Line] = None
previous_after: int = 0
- previous_defs: List[int] = Factory(list)
+ previous_defs: List[int] = field(default_factory=list)
def maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]:
"""Return the number of extra empty lines before and after the `current_line`.
This is for separating `def`, `async def` and `class` with extra empty
lines (two on module-level).
"""
- if isinstance(current_line, UnformattedLines):
- return 0, 0
-
before, after = self._maybe_empty_lines(current_line)
- before -= self.previous_after
+ before = (
+ # Black should not insert empty lines at the beginning
+ # of the file
+ 0
+ if self.previous_line is None
+ else before - self.previous_after
+ )
self.previous_after = after
self.previous_line = current_line
return before, after
before = 0 if depth else 1
else:
before = 1 if depth else 2
- is_decorator = current_line.is_decorator
- if is_decorator or current_line.is_def or current_line.is_class:
- if not is_decorator:
- self.previous_defs.append(depth)
- if self.previous_line is None:
- # Don't insert empty lines before the first line in the file.
- return 0, 0
-
- if self.previous_line.is_decorator:
- return 0, 0
-
- if self.previous_line.depth < current_line.depth and (
- self.previous_line.is_class or self.previous_line.is_def
- ):
- return 0, 0
-
- if (
- self.previous_line.is_comment
- and self.previous_line.depth == current_line.depth
- and before == 0
- ):
- return 0, 0
-
- if self.is_pyi:
- if self.previous_line.depth > current_line.depth:
- newlines = 1
- elif current_line.is_class or self.previous_line.is_class:
- if current_line.is_stub_class and self.previous_line.is_stub_class:
- newlines = 0
- else:
- newlines = 1
- else:
- newlines = 0
- else:
- newlines = 2
- if current_line.depth and newlines:
- newlines -= 1
- return newlines, 0
+ if current_line.is_decorator or current_line.is_def or current_line.is_class:
+ return self._maybe_empty_lines_for_class_or_def(current_line, before)
if (
self.previous_line
return before, 0
+ def _maybe_empty_lines_for_class_or_def(
+ self, current_line: Line, before: int
+ ) -> Tuple[int, int]:
+ if not current_line.is_decorator:
+ self.previous_defs.append(current_line.depth)
+ if self.previous_line is None:
+ # Don't insert empty lines before the first line in the file.
+ return 0, 0
+
+ if self.previous_line.is_decorator:
+ return 0, 0
+
+ if self.previous_line.depth < current_line.depth and (
+ self.previous_line.is_class or self.previous_line.is_def
+ ):
+ return 0, 0
+
+ if (
+ self.previous_line.is_comment
+ and self.previous_line.depth == current_line.depth
+ and before == 0
+ ):
+ return 0, 0
+
+ if self.is_pyi:
+ if self.previous_line.depth > current_line.depth:
+ newlines = 1
+ elif current_line.is_class or self.previous_line.is_class:
+ if current_line.is_stub_class and self.previous_line.is_stub_class:
+ # No blank line between classes with an empty body
+ newlines = 0
+ else:
+ newlines = 1
+ elif current_line.is_def and not self.previous_line.is_def:
+ # Blank line between a block of functions and a block of non-functions
+ newlines = 1
+ else:
+ newlines = 0
+ else:
+ newlines = 2
+ if current_line.depth and newlines:
+ newlines -= 1
+ return newlines, 0
+
@dataclass
class LineGenerator(Visitor[Line]):
is_pyi: bool = False
normalize_strings: bool = True
- current_line: Line = Factory(Line)
+ current_line: Line = field(default_factory=Line)
remove_u_prefix: bool = False
- def line(self, indent: int = 0, type: Type[Line] = Line) -> Iterator[Line]:
+ def line(self, indent: int = 0) -> Iterator[Line]:
"""Generate a line.
If the line is empty, only emit if it makes sense.
If any lines were generated, set up a new current_line.
"""
if not self.current_line:
- if self.current_line.__class__ == type:
- self.current_line.depth += indent
- else:
- self.current_line = type(depth=self.current_line.depth + indent)
+ self.current_line.depth += indent
return # Line is empty, don't emit. Creating a new one unnecessary.
complete_line = self.current_line
- self.current_line = type(depth=complete_line.depth + indent)
+ self.current_line = Line(depth=complete_line.depth + indent)
yield complete_line
- def visit(self, node: LN) -> Iterator[Line]:
- """Main method to visit `node` and its children.
-
- Yields :class:`Line` objects.
- """
- if isinstance(self.current_line, UnformattedLines):
- # File contained `# fmt: off`
- yield from self.visit_unformatted(node)
-
- else:
- yield from super().visit(node)
-
def visit_default(self, node: LN) -> Iterator[Line]:
"""Default `visit_*()` implementation. Recurses to children of `node`."""
if isinstance(node, Leaf):
any_open_brackets = self.current_line.bracket_tracker.any_open_brackets()
- try:
- for comment in generate_comments(node):
- if any_open_brackets:
- # any comment within brackets is subject to splitting
- self.current_line.append(comment)
- elif comment.type == token.COMMENT:
- # regular trailing comment
- self.current_line.append(comment)
- yield from self.line()
-
- else:
- # regular standalone comment
- yield from self.line()
-
- self.current_line.append(comment)
- yield from self.line()
-
- except FormatOff as f_off:
- f_off.trim_prefix(node)
- yield from self.line(type=UnformattedLines)
- yield from self.visit(node)
-
- except FormatOn as f_on:
- # This only happens here if somebody says "fmt: on" multiple
- # times in a row.
- f_on.trim_prefix(node)
- yield from self.visit_default(node)
+ for comment in generate_comments(node):
+ if any_open_brackets:
+ # any comment within brackets is subject to splitting
+ self.current_line.append(comment)
+ elif comment.type == token.COMMENT:
+ # regular trailing comment
+ self.current_line.append(comment)
+ yield from self.line()
- else:
- normalize_prefix(node, inside_brackets=any_open_brackets)
- if self.normalize_strings and node.type == token.STRING:
- normalize_string_prefix(node, remove_u_prefix=self.remove_u_prefix)
- normalize_string_quotes(node)
- if node.type not in WHITESPACE:
- self.current_line.append(node)
+ else:
+ # regular standalone comment
+ yield from self.line()
+
+ self.current_line.append(comment)
+ yield from self.line()
+
+ normalize_prefix(node, inside_brackets=any_open_brackets)
+ if self.normalize_strings and node.type == token.STRING:
+ normalize_string_prefix(node, remove_u_prefix=self.remove_u_prefix)
+ normalize_string_quotes(node)
+ if node.type == token.NUMBER:
+ normalize_numeric_literal(node)
+ if node.type not in WHITESPACE:
+ self.current_line.append(node)
yield from super().visit_default(node)
- def visit_INDENT(self, node: Node) -> Iterator[Line]:
+ def visit_INDENT(self, node: Leaf) -> Iterator[Line]:
"""Increase indentation level, maybe yield a line."""
# In blib2to3 INDENT never holds comments.
yield from self.line(+1)
yield from self.visit_default(node)
- def visit_DEDENT(self, node: Node) -> Iterator[Line]:
+ def visit_DEDENT(self, node: Leaf) -> Iterator[Line]:
"""Decrease indentation level, maybe yield a line."""
# The current line might still wait for trailing comments. At DEDENT time
# there won't be any (they would be prefixes on the preceding NEWLINE).
yield from self.visit_default(leaf)
yield from self.line()
- def visit_unformatted(self, node: LN) -> Iterator[Line]:
- """Used when file contained a `# fmt: off`."""
- if isinstance(node, Node):
- for child in node.children:
- yield from self.visit(child)
+ def visit_STANDALONE_COMMENT(self, leaf: Leaf) -> Iterator[Line]:
+ if not self.current_line.bracket_tracker.any_open_brackets():
+ yield from self.line()
+ yield from self.visit_default(leaf)
- else:
- try:
- self.current_line.append(node)
- except FormatOn as f_on:
- f_on.trim_prefix(node)
- yield from self.line()
- yield from self.visit(node)
+ def visit_factor(self, node: Node) -> Iterator[Line]:
+ """Force parentheses between a unary op and a binary power:
- if node.type == token.ENDMARKER:
- # somebody decided not to put a final `# fmt: on`
- yield from self.line()
+ -2 ** 8 -> -(2 ** 8)
+ """
+ _operator, operand = node.children
+ if (
+ operand.type == syms.power
+ and len(operand.children) == 3
+ and operand.children[1].type == token.DOUBLESTAR
+ ):
+ lpar = Leaf(token.LPAR, "(")
+ rpar = Leaf(token.RPAR, ")")
+ index = operand.remove() or 0
+ node.insert_child(index, Node(syms.atom, [lpar, operand, rpar]))
+ yield from self.visit_default(node)
- def __attrs_post_init__(self) -> None:
+ def __post_init__(self) -> None:
"""You are in a twisty little maze of passages."""
v = self.visit_stmt
Ø: Set[str] = set()
self.visit_expr_stmt = partial(v, keywords=Ø, parens=ASSIGNMENTS)
self.visit_return_stmt = partial(v, keywords={"return"}, parens={"return"})
self.visit_import_from = partial(v, keywords=Ø, parens={"import"})
+ self.visit_del_stmt = partial(v, keywords=Ø, parens={"del"})
self.visit_async_funcdef = self.visit_async_stmt
self.visit_decorated = self.visit_decorators
ALWAYS_NO_SPACE = CLOSING_BRACKETS | {token.COMMA, STANDALONE_COMMENT}
-def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str: # noqa C901
+def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str: # noqa: C901
"""Return whitespace prefix if needed for the given `leaf`.
`complex_subscript` signals whether the given leaf is part of a subscription
# that, too.
return prevp.prefix
- elif prevp.type in STARS:
+ elif prevp.type in VARARGS_SPECIALS:
if is_vararg(prevp, within=VARARGS_PARENTS | UNPACKING_PARENTS):
return NO
if not prevp or prevp.type == token.LPAR:
return NO
- elif prev.type in {token.EQUAL} | STARS:
+ elif prev.type in {token.EQUAL} | VARARGS_SPECIALS:
return NO
elif p.type == syms.decorator:
elif prevp.type == token.EQUAL and prevp_parent.type == syms.argument:
return NO
- elif t == token.NAME or t == token.NUMBER:
+ elif t in {token.NAME, token.NUMBER, token.STRING}:
return NO
elif p.type == syms.import_from:
return None
-def child_towards(ancestor: Node, descendant: LN) -> Optional[LN]:
- """Return the child of `ancestor` that contains `descendant`."""
- node: Optional[LN] = descendant
- while node and node.parent != ancestor:
- node = node.parent
- return node
+def child_towards(ancestor: Node, descendant: LN) -> Optional[LN]:
+ """Return the child of `ancestor` that contains `descendant`."""
+ node: Optional[LN] = descendant
+ while node and node.parent != ancestor:
+ node = node.parent
+ return node
+
+
+def container_of(leaf: Leaf) -> LN:
+ """Return `leaf` or one of its ancestors that is the topmost container of it.
+
+ By "container" we mean a node where `leaf` is the very first child.
+ """
+ same_prefix = leaf.prefix
+ container: LN = leaf
+ while container:
+ parent = container.parent
+ if parent is None:
+ break
+
+ if parent.children[0].prefix != same_prefix:
+ break
+
+ if parent.type == syms.file_input:
+ break
+
+ if parent.prev_sibling is not None and parent.prev_sibling.type in BRACKETS:
+ break
+
+ container = parent
+ return container
-def is_split_after_delimiter(leaf: Leaf, previous: Leaf = None) -> int:
+def is_split_after_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> Priority:
"""Return the priority of the `leaf` delimiter, given a line break after it.
The delimiter priorities returned here are from those delimiters that would
return 0
-def is_split_before_delimiter(leaf: Leaf, previous: Leaf = None) -> int:
- """Return the priority of the `leaf` delimiter, given a line before after it.
+def is_split_before_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> Priority:
+ """Return the priority of the `leaf` delimiter, given a line break before it.
The delimiter priorities returned here are from those delimiters that would
cause a line break before themselves.
):
return STRING_PRIORITY
- if leaf.type != token.NAME:
+ if leaf.type not in {token.NAME, token.ASYNC}:
return 0
if (
leaf.value == "for"
and leaf.parent
and leaf.parent.type in {syms.comp_for, syms.old_comp_for}
+ or leaf.type == token.ASYNC
):
- return COMPREHENSION_PRIORITY
+ if (
+ not isinstance(leaf.prev_sibling, Leaf)
+ or leaf.prev_sibling.value != "async"
+ ):
+ return COMPREHENSION_PRIORITY
if (
leaf.value == "if"
return 0
+FMT_OFF = {"# fmt: off", "# fmt:off", "# yapf: disable"}
+FMT_ON = {"# fmt: on", "# fmt:on", "# yapf: enable"}
+
+
def generate_comments(leaf: LN) -> Iterator[Leaf]:
"""Clean the prefix of the `leaf` and generate comments from it, if any.
Inline comments are emitted as regular token.COMMENT leaves. Standalone
are emitted with a fake STANDALONE_COMMENT token identifier.
"""
- p = leaf.prefix
- if not p:
- return
+ for pc in list_comments(leaf.prefix, is_endmarker=leaf.type == token.ENDMARKER):
+ yield Leaf(pc.type, pc.value, prefix="\n" * pc.newlines)
- if "#" not in p:
- return
+
+@dataclass
+class ProtoComment:
+ """Describes a piece of syntax that is a comment.
+
+ It's not a :class:`blib2to3.pytree.Leaf` so that:
+
+ * it can be cached (`Leaf` objects should not be reused more than once as
+ they store their lineno, column, prefix, and parent information);
+ * `newlines` and `consumed` fields are kept separate from the `value`. This
+ simplifies handling of special marker comments like ``# fmt: off/on``.
+ """
+
+ type: int # token.COMMENT or STANDALONE_COMMENT
+ value: str # content of the comment
+ newlines: int # how many newlines before the comment
+ consumed: int # how many characters of the original leaf's prefix did we consume
+
+
+@lru_cache(maxsize=4096)
+def list_comments(prefix: str, *, is_endmarker: bool) -> List[ProtoComment]:
+ """Return a list of :class:`ProtoComment` objects parsed from the given `prefix`."""
+ result: List[ProtoComment] = []
+ if not prefix or "#" not in prefix:
+ return result
consumed = 0
nlines = 0
- for index, line in enumerate(p.split("\n")):
+ ignored_lines = 0
+ for index, line in enumerate(prefix.split("\n")):
consumed += len(line) + 1 # adding the length of the split '\n'
line = line.lstrip()
if not line:
nlines += 1
if not line.startswith("#"):
+ # Escaped newlines outside of a comment are not really newlines at
+ # all. We treat a single-line comment following an escaped newline
+ # as a simple trailing comment.
+ if line.endswith("\\"):
+ ignored_lines += 1
continue
- if index == 0 and leaf.type != token.ENDMARKER:
+ if index == ignored_lines and not is_endmarker:
comment_type = token.COMMENT # simple trailing comment
else:
comment_type = STANDALONE_COMMENT
comment = make_comment(line)
- yield Leaf(comment_type, comment, prefix="\n" * nlines)
-
- if comment in {"# fmt: on", "# yapf: enable"}:
- raise FormatOn(consumed)
-
- if comment in {"# fmt: off", "# yapf: disable"}:
- if comment_type == STANDALONE_COMMENT:
- raise FormatOff(consumed)
-
- prev = preceding_leaf(leaf)
- if not prev or prev.type in WHITESPACE: # standalone comment in disguise
- raise FormatOff(consumed)
-
+ result.append(
+ ProtoComment(
+ type=comment_type, value=comment, newlines=nlines, consumed=consumed
+ )
+ )
nlines = 0
+ return result
def make_comment(content: str) -> str:
"""Return a consistently formatted comment from the given `content` string.
- All comments (except for "##", "#!", "#:") should have a single space between
- the hash sign and the content.
+ All comments (except for "##", "#!", "#:", '#'", "#%%") should have a single
+ space between the hash sign and the content.
If `content` didn't start with a hash sign, one is provided.
"""
if content[0] == "#":
content = content[1:]
- if content and content[0] not in " !:#":
+ if content and content[0] not in " !:#'%":
content = " " + content
return "#" + content
def split_line(
- line: Line, line_length: int, inner: bool = False, py36: bool = False
+ line: Line,
+ line_length: int,
+ inner: bool = False,
+ features: Collection[Feature] = (),
) -> Iterator[Line]:
"""Split a `line` into potentially many lines.
current `line`, possibly transitively. This means we can fallback to splitting
by delimiters if the LHS/RHS don't yield any results.
- If `py36` is True, splitting may generate syntax that is only compatible
- with Python 3.6 and later.
+ `features` are syntactical features that may be used in the output.
"""
- if isinstance(line, UnformattedLines) or line.is_comment:
+ if line.is_comment:
yield line
return
line_str = str(line).strip("\n")
- if not line.should_explode and is_line_short_enough(
- line, line_length=line_length, line_str=line_str
+
+ if (
+ not line.contains_uncollapsable_type_comments()
+ and not line.should_explode
+ and not line.is_collection_with_optional_trailing_comma
+ and (
+ is_line_short_enough(line, line_length=line_length, line_str=line_str)
+ or line.contains_unsplittable_type_ignore()
+ )
):
yield line
return
split_funcs = [left_hand_split]
else:
- def rhs(line: Line, py36: bool = False) -> Iterator[Line]:
+ def rhs(line: Line, features: Collection[Feature]) -> Iterator[Line]:
for omit in generate_trailers_to_omit(line, line_length):
- lines = list(right_hand_split(line, line_length, py36, omit=omit))
+ lines = list(right_hand_split(line, line_length, features, omit=omit))
if is_line_short_enough(lines[0], line_length=line_length):
yield from lines
return
# All splits failed, best effort split with no omits.
# This mostly happens to multiline strings that are by definition
# reported as not fitting a single line.
- yield from right_hand_split(line, py36)
+ # line_length=1 here was historically a bug that somehow became a feature.
+ # See #762 and #781 for the full story.
+ yield from right_hand_split(line, line_length=1, features=features)
if line.inside_brackets:
split_funcs = [delimiter_split, standalone_comment_split, rhs]
# split altogether.
result: List[Line] = []
try:
- for l in split_func(line, py36):
+ for l in split_func(line, features):
if str(l).strip("\n") == line_str:
raise CannotSplit("Split function returned an unchanged result")
result.extend(
- split_line(l, line_length=line_length, inner=True, py36=py36)
+ split_line(
+ l, line_length=line_length, inner=True, features=features
+ )
)
- except CannotSplit as cs:
+ except CannotSplit:
continue
else:
yield line
-def left_hand_split(line: Line, py36: bool = False) -> Iterator[Line]:
+def left_hand_split(line: Line, features: Collection[Feature] = ()) -> Iterator[Line]:
"""Split line into many lines, starting with the first matching bracket pair.
Note: this usually looks weird, only use this for function definitions.
Prefer RHS otherwise. This is why this function is not symmetrical with
:func:`right_hand_split` which also handles optional parentheses.
"""
- head = Line(depth=line.depth)
- body = Line(depth=line.depth + 1, inside_brackets=True)
- tail = Line(depth=line.depth)
tail_leaves: List[Leaf] = []
body_leaves: List[Leaf] = []
head_leaves: List[Leaf] = []
current_leaves = head_leaves
- matching_bracket = None
+ matching_bracket: Optional[Leaf] = None
for leaf in line.leaves:
if (
current_leaves is body_leaves
if leaf.type in OPENING_BRACKETS:
matching_bracket = leaf
current_leaves = body_leaves
- # Since body is a new indent level, remove spurious leading whitespace.
- if body_leaves:
- normalize_prefix(body_leaves[0], inside_brackets=True)
- # Build the new lines.
- for result, leaves in (head, head_leaves), (body, body_leaves), (tail, tail_leaves):
- for leaf in leaves:
- result.append(leaf, preformatted=True)
- for comment_after in line.comments_after(leaf):
- result.append(comment_after, preformatted=True)
+ if not matching_bracket:
+ raise CannotSplit("No brackets found")
+
+ head = bracket_split_build_line(head_leaves, line, matching_bracket)
+ body = bracket_split_build_line(body_leaves, line, matching_bracket, is_body=True)
+ tail = bracket_split_build_line(tail_leaves, line, matching_bracket)
bracket_split_succeeded_or_raise(head, body, tail)
for result in (head, body, tail):
if result:
def right_hand_split(
- line: Line, line_length: int, py36: bool = False, omit: Collection[LeafID] = ()
+ line: Line,
+ line_length: int,
+ features: Collection[Feature] = (),
+ omit: Collection[LeafID] = (),
) -> Iterator[Line]:
"""Split line into many lines, starting with the last matching bracket pair.
Note: running this function modifies `bracket_depth` on the leaves of `line`.
"""
- head = Line(depth=line.depth)
- body = Line(depth=line.depth + 1, inside_brackets=True)
- tail = Line(depth=line.depth)
tail_leaves: List[Leaf] = []
body_leaves: List[Leaf] = []
head_leaves: List[Leaf] = []
current_leaves = tail_leaves
- opening_bracket = None
- closing_bracket = None
+ opening_bracket: Optional[Leaf] = None
+ closing_bracket: Optional[Leaf] = None
for leaf in reversed(line.leaves):
if current_leaves is body_leaves:
if leaf is opening_bracket:
opening_bracket = leaf.opening_bracket
closing_bracket = leaf
current_leaves = body_leaves
- tail_leaves.reverse()
- body_leaves.reverse()
- head_leaves.reverse()
- # Since body is a new indent level, remove spurious leading whitespace.
- if body_leaves:
- normalize_prefix(body_leaves[0], inside_brackets=True)
- if not head_leaves:
- # No `head` means the split failed. Either `tail` has all content or
+ if not (opening_bracket and closing_bracket and head_leaves):
+ # If there is no opening or closing_bracket that means the split failed and
+ # all content is in the tail. Otherwise, if `head_leaves` are empty, it means
# the matching `opening_bracket` wasn't available on `line` anymore.
raise CannotSplit("No brackets found")
- # Build the new lines.
- for result, leaves in (head, head_leaves), (body, body_leaves), (tail, tail_leaves):
- for leaf in leaves:
- result.append(leaf, preformatted=True)
- for comment_after in line.comments_after(leaf):
- result.append(comment_after, preformatted=True)
+ tail_leaves.reverse()
+ body_leaves.reverse()
+ head_leaves.reverse()
+ head = bracket_split_build_line(head_leaves, line, opening_bracket)
+ body = bracket_split_build_line(body_leaves, line, opening_bracket, is_body=True)
+ tail = bracket_split_build_line(tail_leaves, line, opening_bracket)
bracket_split_succeeded_or_raise(head, body, tail)
- assert opening_bracket and closing_bracket
if (
+ # the body shouldn't be exploded
+ not body.should_explode
# the opening bracket is an optional paren
- opening_bracket.type == token.LPAR
+ and opening_bracket.type == token.LPAR
and not opening_bracket.value
# the closing bracket is an optional paren
and closing_bracket.type == token.RPAR
and not closing_bracket.value
- # there are no standalone comments in the body
- and not line.contains_standalone_comments(0)
- # and it's not an import (optional parens are the only thing we can split
- # on in this case; attempting a split without them is a waste of time)
+ # it's not an import (optional parens are the only thing we can split on
+ # in this case; attempting a split without them is a waste of time)
and not line.is_import
+ # there are no standalone comments in the body
+ and not body.contains_standalone_comments(0)
+ # and we can actually remove the parens
+ and can_omit_invisible_parens(body, line_length)
):
omit = {id(closing_bracket), *omit}
- if can_omit_invisible_parens(body, line_length):
- try:
- yield from right_hand_split(line, line_length, py36=py36, omit=omit)
- return
- except CannotSplit:
- pass
+ try:
+ yield from right_hand_split(line, line_length, features=features, omit=omit)
+ return
+
+ except CannotSplit:
+ if not (
+ can_be_split(body)
+ or is_line_short_enough(body, line_length=line_length)
+ ):
+ raise CannotSplit(
+ "Splitting failed, body is still too long and can't be split."
+ )
+
+ elif head.contains_multiline_strings() or tail.contains_multiline_strings():
+ raise CannotSplit(
+ "The current optional pair of parentheses is bound to fail to "
+ "satisfy the splitting algorithm because the head or the tail "
+ "contains multiline strings which by definition never fit one "
+ "line."
+ )
ensure_visible(opening_bracket)
ensure_visible(closing_bracket)
- body.should_explode = should_explode(body, opening_bracket)
for result in (head, body, tail):
if result:
yield result
)
+def bracket_split_build_line(
+ leaves: List[Leaf], original: Line, opening_bracket: Leaf, *, is_body: bool = False
+) -> Line:
+ """Return a new line with given `leaves` and respective comments from `original`.
+
+ If `is_body` is True, the result line is one-indented inside brackets and as such
+ has its first leaf's prefix normalized and a trailing comma added when expected.
+ """
+ result = Line(depth=original.depth)
+ if is_body:
+ result.inside_brackets = True
+ result.depth += 1
+ if leaves:
+ # Since body is a new indent level, remove spurious leading whitespace.
+ normalize_prefix(leaves[0], inside_brackets=True)
+ # Ensure a trailing comma for imports and standalone function arguments, but
+ # be careful not to add one after any comments or within type annotations.
+ no_commas = (
+ original.is_def
+ and opening_bracket.value == "("
+ and not any(l.type == token.COMMA for l in leaves)
+ )
+
+ if original.is_import or no_commas:
+ for i in range(len(leaves) - 1, -1, -1):
+ if leaves[i].type == STANDALONE_COMMENT:
+ continue
+
+ if leaves[i].type != token.COMMA:
+ leaves.insert(i + 1, Leaf(token.COMMA, ","))
+ break
+
+ # Populate the line
+ for leaf in leaves:
+ result.append(leaf, preformatted=True)
+ for comment_after in original.comments_after(leaf):
+ result.append(comment_after, preformatted=True)
+ if is_body:
+ result.should_explode = should_explode(result, opening_bracket)
+ return result
+
+
def dont_increase_indentation(split_func: SplitFunc) -> SplitFunc:
"""Normalize prefix of the first leaf in every line returned by `split_func`.
"""
@wraps(split_func)
- def split_wrapper(line: Line, py36: bool = False) -> Iterator[Line]:
- for l in split_func(line, py36):
+ def split_wrapper(line: Line, features: Collection[Feature] = ()) -> Iterator[Line]:
+ for l in split_func(line, features):
normalize_prefix(l.leaves[0], inside_brackets=True)
yield l
@dont_increase_indentation
-def delimiter_split(line: Line, py36: bool = False) -> Iterator[Line]:
+def delimiter_split(line: Line, features: Collection[Feature] = ()) -> Iterator[Line]:
"""Split according to delimiters of the highest priority.
- If `py36` is True, the split will add trailing commas also in function
- signatures that contain `*` and `**`.
+ If the appropriate Features are given, the split will add trailing commas
+ also in function signatures and calls that contain `*` and `**`.
"""
try:
last_leaf = line.leaves[-1]
nonlocal current_line
try:
current_line.append_safe(leaf, preformatted=True)
- except ValueError as ve:
+ except ValueError:
yield current_line
current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets)
current_line.append(leaf)
- for index, leaf in enumerate(line.leaves):
+ for leaf in line.leaves:
yield from append_to_line(leaf)
- for comment_after in line.comments_after(leaf, index):
+ for comment_after in line.comments_after(leaf):
yield from append_to_line(comment_after)
lowest_depth = min(lowest_depth, leaf.bracket_depth)
- if leaf.bracket_depth == lowest_depth and is_vararg(
- leaf, within=VARARGS_PARENTS
- ):
- trailing_comma_safe = trailing_comma_safe and py36
+ if leaf.bracket_depth == lowest_depth:
+ if is_vararg(leaf, within={syms.typedargslist}):
+ trailing_comma_safe = (
+ trailing_comma_safe and Feature.TRAILING_COMMA_IN_DEF in features
+ )
+ elif is_vararg(leaf, within={syms.arglist, syms.argument}):
+ trailing_comma_safe = (
+ trailing_comma_safe and Feature.TRAILING_COMMA_IN_CALL in features
+ )
+
leaf_priority = bt.delimiters.get(id(leaf))
if leaf_priority == delimiter_priority:
yield current_line
@dont_increase_indentation
-def standalone_comment_split(line: Line, py36: bool = False) -> Iterator[Line]:
+def standalone_comment_split(
+ line: Line, features: Collection[Feature] = ()
+) -> Iterator[Line]:
"""Split standalone comments from the rest of the line."""
if not line.contains_standalone_comments(0):
raise CannotSplit("Line does not have any standalone comments")
nonlocal current_line
try:
current_line.append_safe(leaf, preformatted=True)
- except ValueError as ve:
+ except ValueError:
yield current_line
current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets)
current_line.append(leaf)
- for index, leaf in enumerate(line.leaves):
+ for leaf in line.leaves:
yield from append_to_line(leaf)
- for comment_after in line.comments_after(leaf, index):
+ for comment_after in line.comments_after(leaf):
yield from append_to_line(comment_after)
if current_line:
)
+def is_type_comment(leaf: Leaf, suffix: str = "") -> bool:
+ """Return True if the given leaf is a special comment.
+ Only returns true for type comments for now."""
+ t = leaf.type
+ v = leaf.value
+ return t in {token.COMMENT, STANDALONE_COMMENT} and v.startswith("# type:" + suffix)
+
+
def normalize_prefix(leaf: Leaf, *, inside_brackets: bool) -> None:
"""Leave existing extra newlines if not `inside_brackets`. Remove everything
else.
match = re.match(r"^([furbFURB]*)(.*)$", leaf.value, re.DOTALL)
assert match is not None, f"failed to match string {leaf.value!r}"
orig_prefix = match.group(1)
- new_prefix = orig_prefix.lower()
+ new_prefix = orig_prefix.replace("F", "f").replace("B", "b").replace("U", "u")
if remove_u_prefix:
new_prefix = new_prefix.replace("u", "")
leaf.value = f"{new_prefix}{match.group(2)}"
prefix = leaf.value[:first_quote_pos]
unescaped_new_quote = re.compile(rf"(([^\\]|^)(\\\\)*){new_quote}")
- escaped_new_quote = re.compile(rf"([^\\]|^)\\(\\\\)*{new_quote}")
- escaped_orig_quote = re.compile(rf"([^\\]|^)\\(\\\\)*{orig_quote}")
+ escaped_new_quote = re.compile(rf"([^\\]|^)\\((?:\\\\)*){new_quote}")
+ escaped_orig_quote = re.compile(rf"([^\\]|^)\\((?:\\\\)*){orig_quote}")
body = leaf.value[first_quote_pos + len(orig_quote) : -len(orig_quote)]
if "r" in prefix.casefold():
if unescaped_new_quote.search(body):
# Do not introduce or remove backslashes in raw strings
new_body = body
else:
- # remove unnecessary quotes
+ # remove unnecessary escapes
new_body = sub_twice(escaped_new_quote, rf"\1\2{new_quote}", body)
if body != new_body:
- # Consider the string without unnecessary quotes as the original
+ # Consider the string without unnecessary escapes as the original
body = new_body
leaf.value = f"{prefix}{orig_quote}{body}{orig_quote}"
new_body = sub_twice(escaped_orig_quote, rf"\1\2{orig_quote}", new_body)
new_body = sub_twice(unescaped_new_quote, rf"\1\\{new_quote}", new_body)
- if new_quote == '"""' and new_body[-1] == '"':
+ if "f" in prefix.casefold():
+ matches = re.findall(
+ r"""
+ (?:[^{]|^)\{ # start of the string or a non-{ followed by a single {
+ ([^{].*?) # contents of the brackets except if begins with {{
+ \}(?:[^}]|$) # A } followed by end of the string or a non-}
+ """,
+ new_body,
+ re.VERBOSE,
+ )
+ for m in matches:
+ if "\\" in str(m):
+ # Do not introduce backslashes in interpolated expressions
+ return
+
+ if new_quote == '"""' and new_body[-1:] == '"':
# edge case:
new_body = new_body[:-1] + '\\"'
orig_escape_count = body.count("\\")
leaf.value = f"{prefix}{new_quote}{new_body}{new_quote}"
+def normalize_numeric_literal(leaf: Leaf) -> None:
+ """Normalizes numeric (float, int, and complex) literals.
+
+ All letters used in the representation are normalized to lowercase (except
+ in Python 2 long literals).
+ """
+ text = leaf.value.lower()
+ if text.startswith(("0o", "0b")):
+ # Leave octal and binary literals alone.
+ pass
+ elif text.startswith("0x"):
+ # Change hex literals to upper case.
+ before, after = text[:2], text[2:]
+ text = f"{before}{after.upper()}"
+ elif "e" in text:
+ before, after = text.split("e")
+ sign = ""
+ if after.startswith("-"):
+ after = after[1:]
+ sign = "-"
+ elif after.startswith("+"):
+ after = after[1:]
+ before = format_float_or_int_string(before)
+ text = f"{before}e{sign}{after}"
+ elif text.endswith(("j", "l")):
+ number = text[:-1]
+ suffix = text[-1]
+ # Capitalize in "2L" because "l" looks too similar to "1".
+ if suffix == "l":
+ suffix = "L"
+ text = f"{format_float_or_int_string(number)}{suffix}"
+ else:
+ text = format_float_or_int_string(text)
+ leaf.value = text
+
+
+def format_float_or_int_string(text: str) -> str:
+ """Formats a float string like "1.0"."""
+ if "." not in text:
+ return text
+
+ before, after = text.split(".")
+ return f"{before or 0}.{after or 0}"
+
+
def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None:
"""Make existing optional parentheses invisible or create new ones.
- `parens_after` is a set of string leaf values immeditely after which parens
+ `parens_after` is a set of string leaf values immediately after which parens
should be put.
Standardizes on visible parentheses for single-element tuples, and keeps
existing visible parentheses for other tuples and generator expressions.
"""
- try:
- list(generate_comments(node))
- except FormatOff:
- return # This `node` has a prefix with `# fmt: off`, don't mess with parens.
-
+ for pc in list_comments(node.prefix, is_endmarker=False):
+ if pc.value in FMT_OFF:
+ # This `node` has a prefix with `# fmt: off`, don't mess with parens.
+ return
check_lpar = False
for index, child in enumerate(list(node.children)):
+ # Add parentheses around long tuple unpacking in assignments.
+ if (
+ index == 0
+ and isinstance(child, Node)
+ and child.type == syms.testlist_star_expr
+ ):
+ check_lpar = True
+
if check_lpar:
+ if is_walrus_assignment(child):
+ continue
+
if child.type == syms.atom:
- maybe_make_parens_invisible_in_atom(child)
+ if maybe_make_parens_invisible_in_atom(child, parent=node):
+ wrap_in_parentheses(node, child, visible=False)
elif is_one_tuple(child):
- # wrap child in visible parentheses
- lpar = Leaf(token.LPAR, "(")
- rpar = Leaf(token.RPAR, ")")
- child.remove()
- node.insert_child(index, Node(syms.atom, [lpar, child, rpar]))
+ wrap_in_parentheses(node, child, visible=True)
elif node.type == syms.import_from:
# "import from" nodes store parentheses directly as part of
# the statement
break
elif not (isinstance(child, Leaf) and is_multiline_string(child)):
- # wrap child in invisible parentheses
- lpar = Leaf(token.LPAR, "")
- rpar = Leaf(token.RPAR, "")
- index = child.remove() or 0
- node.insert_child(index, Node(syms.atom, [lpar, child, rpar]))
+ wrap_in_parentheses(node, child, visible=False)
check_lpar = isinstance(child, Leaf) and child.value in parens_after
-def maybe_make_parens_invisible_in_atom(node: LN) -> bool:
- """If it's safe, make the parens in the atom `node` invisible, recusively."""
+def normalize_fmt_off(node: Node) -> None:
+ """Convert content between `# fmt: off`/`# fmt: on` into standalone comments."""
+ try_again = True
+ while try_again:
+ try_again = convert_one_fmt_off_pair(node)
+
+
+def convert_one_fmt_off_pair(node: Node) -> bool:
+ """Convert content of a single `# fmt: off`/`# fmt: on` into a standalone comment.
+
+ Returns True if a pair was converted.
+ """
+ for leaf in node.leaves():
+ previous_consumed = 0
+ for comment in list_comments(leaf.prefix, is_endmarker=False):
+ if comment.value in FMT_OFF:
+ # We only want standalone comments. If there's no previous leaf or
+ # the previous leaf is indentation, it's a standalone comment in
+ # disguise.
+ if comment.type != STANDALONE_COMMENT:
+ prev = preceding_leaf(leaf)
+ if prev and prev.type not in WHITESPACE:
+ continue
+
+ ignored_nodes = list(generate_ignored_nodes(leaf))
+ if not ignored_nodes:
+ continue
+
+ first = ignored_nodes[0] # Can be a container node with the `leaf`.
+ parent = first.parent
+ prefix = first.prefix
+ first.prefix = prefix[comment.consumed :]
+ hidden_value = (
+ comment.value + "\n" + "".join(str(n) for n in ignored_nodes)
+ )
+ if hidden_value.endswith("\n"):
+ # That happens when one of the `ignored_nodes` ended with a NEWLINE
+ # leaf (possibly followed by a DEDENT).
+ hidden_value = hidden_value[:-1]
+ first_idx: Optional[int] = None
+ for ignored in ignored_nodes:
+ index = ignored.remove()
+ if first_idx is None:
+ first_idx = index
+ assert parent is not None, "INTERNAL ERROR: fmt: on/off handling (1)"
+ assert first_idx is not None, "INTERNAL ERROR: fmt: on/off handling (2)"
+ parent.insert_child(
+ first_idx,
+ Leaf(
+ STANDALONE_COMMENT,
+ hidden_value,
+ prefix=prefix[:previous_consumed] + "\n" * comment.newlines,
+ ),
+ )
+ return True
+
+ previous_consumed = comment.consumed
+
+ return False
+
+
+def generate_ignored_nodes(leaf: Leaf) -> Iterator[LN]:
+ """Starting from the container of `leaf`, generate all leaves until `# fmt: on`.
+
+ Stops at the end of the block.
+ """
+ container: Optional[LN] = container_of(leaf)
+ while container is not None and container.type != token.ENDMARKER:
+ is_fmt_on = False
+ for comment in list_comments(container.prefix, is_endmarker=False):
+ if comment.value in FMT_ON:
+ is_fmt_on = True
+ elif comment.value in FMT_OFF:
+ is_fmt_on = False
+ if is_fmt_on:
+ return
+
+ yield container
+
+ container = container.next_sibling
+
+
+def maybe_make_parens_invisible_in_atom(node: LN, parent: LN) -> bool:
+ """If it's safe, make the parens in the atom `node` invisible, recursively.
+ Additionally, remove repeated, adjacent invisible parens from the atom `node`
+ as they are redundant.
+
+ Returns whether the node should itself be wrapped in invisible parentheses.
+
+ """
if (
node.type != syms.atom
or is_empty_tuple(node)
or is_one_tuple(node)
- or is_yield(node)
+ or (is_yield(node) and parent.type != syms.expr_stmt)
or max_delimiter_priority_in_atom(node) >= COMMA_PRIORITY
):
return False
first = node.children[0]
last = node.children[-1]
if first.type == token.LPAR and last.type == token.RPAR:
+ middle = node.children[1]
# make parentheses invisible
first.value = "" # type: ignore
last.value = "" # type: ignore
- if len(node.children) > 1:
- maybe_make_parens_invisible_in_atom(node.children[1])
- return True
+ maybe_make_parens_invisible_in_atom(middle, parent=parent)
- return False
+ if is_atom_with_invisible_parens(middle):
+ # Strip the invisible parens from `middle` by replacing
+ # it with the child in-between the invisible parens
+ middle.replace(middle.children[1])
+
+ return False
+
+ return True
+
+
+def is_atom_with_invisible_parens(node: LN) -> bool:
+ """Given a `LN`, determines whether it's an atom `node` with invisible
+ parens. Useful in dedupe-ing and normalizing parens.
+ """
+ if isinstance(node, Leaf) or node.type != syms.atom:
+ return False
+
+ first, last = node.children[0], node.children[-1]
+ return (
+ isinstance(first, Leaf)
+ and first.type == token.LPAR
+ and first.value == ""
+ and isinstance(last, Leaf)
+ and last.type == token.RPAR
+ and last.value == ""
+ )
def is_empty_tuple(node: LN) -> bool:
)
+def unwrap_singleton_parenthesis(node: LN) -> Optional[LN]:
+ """Returns `wrapped` if `node` is of the shape ( wrapped ).
+
+ Parenthesis can be optional. Returns None otherwise"""
+ if len(node.children) != 3:
+ return None
+
+ lpar, wrapped, rpar = node.children
+ if not (lpar.type == token.LPAR and rpar.type == token.RPAR):
+ return None
+
+ return wrapped
+
+
+def wrap_in_parentheses(parent: Node, child: LN, *, visible: bool = True) -> None:
+ """Wrap `child` in parentheses.
+
+ This replaces `child` with an atom holding the parentheses and the old
+ child. That requires moving the prefix.
+
+ If `visible` is False, the leaves will be valueless (and thus invisible).
+ """
+ lpar = Leaf(token.LPAR, "(" if visible else "")
+ rpar = Leaf(token.RPAR, ")" if visible else "")
+ prefix = child.prefix
+ child.prefix = ""
+ index = child.remove() or 0
+ new_child = Node(syms.atom, [lpar, child, rpar])
+ new_child.prefix = prefix
+ parent.insert_child(index, new_child)
+
+
def is_one_tuple(node: LN) -> bool:
"""Return True if `node` holds a tuple with one element, with or without parens."""
if node.type == syms.atom:
- if len(node.children) != 3:
- return False
-
- lpar, gexp, rpar = node.children
- if not (
- lpar.type == token.LPAR
- and gexp.type == syms.testlist_gexp
- and rpar.type == token.RPAR
- ):
+ gexp = unwrap_singleton_parenthesis(node)
+ if gexp is None or gexp.type != syms.testlist_gexp:
return False
return len(gexp.children) == 2 and gexp.children[1].type == token.COMMA
)
+def is_walrus_assignment(node: LN) -> bool:
+ """Return True iff `node` is of the shape ( test := test )"""
+ inner = unwrap_singleton_parenthesis(node)
+ return inner is not None and inner.type == syms.namedexpr_test
+
+
def is_yield(node: LN) -> bool:
"""Return True if `node` holds a `yield` or `yield from` expression."""
if node.type == syms.yield_expr:
extended iterable unpacking (PEP 3132) and additional unpacking
generalizations (PEP 448).
"""
- if leaf.type not in STARS or not leaf.parent:
+ if leaf.type not in VARARGS_SPECIALS or not leaf.parent:
return False
p = leaf.parent
)
-def max_delimiter_priority_in_atom(node: LN) -> int:
+def max_delimiter_priority_in_atom(node: LN) -> Priority:
"""Return maximum delimiter priority inside `node`.
This is specific to atoms with contents contained in a pair of parentheses.
"""Make sure parentheses are visible.
They could be invisible as part of some statements (see
- :func:`normalize_invible_parens` and :func:`visit_import_from`).
+ :func:`normalize_invisible_parens` and :func:`visit_import_from`).
"""
if leaf.type == token.LPAR:
leaf.value = "("
def should_explode(line: Line, opening_bracket: Leaf) -> bool:
"""Should `line` immediately be split with `delimiter_split()` after RHS?"""
+
if not (
opening_bracket.parent
and opening_bracket.parent.type in {syms.atom, syms.import_from}
return max_priority == COMMA_PRIORITY
-def is_python36(node: Node) -> bool:
- """Return True if the current file is using Python 3.6+ features.
+def get_features_used(node: Node) -> Set[Feature]:
+ """Return a set of (relatively) new Python features used in this file.
Currently looking for:
- - f-strings; and
- - trailing commas after * or ** in function signatures and calls.
+ - f-strings;
+ - underscores in numeric literals;
+ - trailing commas after * or ** in function signatures and calls;
+ - positional only arguments in function signatures and lambdas;
"""
+ features: Set[Feature] = set()
for n in node.pre_order():
if n.type == token.STRING:
value_head = n.value[:2] # type: ignore
if value_head in {'f"', 'F"', "f'", "F'", "rf", "fr", "RF", "FR"}:
- return True
+ features.add(Feature.F_STRINGS)
+
+ elif n.type == token.NUMBER:
+ if "_" in n.value: # type: ignore
+ features.add(Feature.NUMERIC_UNDERSCORES)
+
+ elif n.type == token.SLASH:
+ if n.parent and n.parent.type in {syms.typedargslist, syms.arglist}:
+ features.add(Feature.POS_ONLY_ARGUMENTS)
+
+ elif n.type == token.COLONEQUAL:
+ features.add(Feature.ASSIGNMENT_EXPRESSIONS)
elif (
n.type in {syms.typedargslist, syms.arglist}
and n.children
and n.children[-1].type == token.COMMA
):
+ if n.type == syms.typedargslist:
+ feature = Feature.TRAILING_COMMA_IN_DEF
+ else:
+ feature = Feature.TRAILING_COMMA_IN_CALL
+
for ch in n.children:
if ch.type in STARS:
- return True
+ features.add(feature)
if ch.type == syms.argument:
for argch in ch.children:
if argch.type in STARS:
- return True
+ features.add(feature)
- return False
+ return features
+
+
+def detect_target_versions(node: Node) -> Set[TargetVersion]:
+ """Detect the version to target based on the nodes used."""
+ features = get_features_used(node)
+ return {
+ version for version in TargetVersion if features <= VERSION_TO_FEATURES[version]
+ }
def generate_trailers_to_omit(line: Line, line_length: int) -> Iterator[Set[LeafID]]:
yield omit
length = 4 * line.depth
- opening_bracket = None
- closing_bracket = None
- optional_brackets: Set[LeafID] = set()
+ opening_bracket: Optional[Leaf] = None
+ closing_bracket: Optional[Leaf] = None
inner_brackets: Set[LeafID] = set()
for index, leaf, leaf_length in enumerate_with_length(line, reversed=True):
length += leaf_length
if leaf.type == STANDALONE_COMMENT or has_inline_comment:
break
- optional_brackets.discard(id(leaf))
if opening_bracket:
if leaf is opening_bracket:
opening_bracket = None
elif leaf.type in CLOSING_BRACKETS:
inner_brackets.add(id(leaf))
elif leaf.type in CLOSING_BRACKETS:
- if not leaf.value:
- optional_brackets.add(id(opening_bracket))
- continue
-
if index > 0 and line.leaves[index - 1].type in OPENING_BRACKETS:
# Empty brackets would fail a split so treat them as "inner"
# brackets (e.g. only add them to the `omit` set if another
inner_brackets.add(id(leaf))
continue
- opening_bracket = leaf.opening_bracket
if closing_bracket:
omit.add(id(closing_bracket))
omit.update(inner_brackets)
inner_brackets.clear()
yield omit
- closing_bracket = leaf
+
+ if leaf.value:
+ opening_bracket = leaf.opening_bracket
+ closing_bracket = leaf
def get_future_imports(node: Node) -> Set[str]:
"""Return a set of __future__ imports in the file."""
- imports = set()
+ imports: Set[str] = set()
+
+ def get_imports_from_children(children: List[LN]) -> Generator[str, None, None]:
+ for child in children:
+ if isinstance(child, Leaf):
+ if child.type == token.NAME:
+ yield child.value
+
+ elif child.type == syms.import_as_name:
+ orig_name = child.children[0]
+ assert isinstance(orig_name, Leaf), "Invalid syntax parsing imports"
+ assert orig_name.type == token.NAME, "Invalid syntax parsing imports"
+ yield orig_name.value
+
+ elif child.type == syms.import_as_names:
+ yield from get_imports_from_children(child.children)
+
+ else:
+ raise AssertionError("Invalid syntax parsing imports")
+
for child in node.children:
if child.type != syms.simple_stmt:
break
+
first_child = child.children[0]
if isinstance(first_child, Leaf):
# Continue looking if we see a docstring; otherwise stop.
and child.children[1].type == token.NEWLINE
):
continue
- else:
- break
+
+ break
+
elif first_child.type == syms.import_from:
module_name = first_child.children[1]
if not isinstance(module_name, Leaf) or module_name.value != "__future__":
break
- for import_from_child in first_child.children[3:]:
- if isinstance(import_from_child, Leaf):
- if import_from_child.type == token.NAME:
- imports.add(import_from_child.value)
- else:
- assert import_from_child.type == syms.import_as_names
- for leaf in import_from_child.children:
- if isinstance(leaf, Leaf) and leaf.type == token.NAME:
- imports.add(leaf.value)
+
+ imports |= set(get_imports_from_children(first_child.children[3:]))
else:
break
+
return imports
+@lru_cache()
+def get_gitignore(root: Path) -> PathSpec:
+ """ Return a PathSpec matching gitignore content if present."""
+ gitignore = root / ".gitignore"
+ lines: List[str] = []
+ if gitignore.is_file():
+ with gitignore.open() as gf:
+ lines = gf.readlines()
+ return PathSpec.from_lines("gitwildmatch", lines)
+
+
def gen_python_files_in_dir(
- path: Path, root: Path, include: Pattern[str], exclude: Pattern[str]
+ path: Path,
+ root: Path,
+ include: Pattern[str],
+ exclude: Pattern[str],
+ report: "Report",
+ gitignore: PathSpec,
) -> Iterator[Path]:
"""Generate all files under `path` whose paths are not excluded by the
`exclude` regex, but are included by the `include` regex.
+
+ Symbolic links pointing outside of the `root` directory are ignored.
+
+ `report` is where output about exclusions goes.
"""
assert root.is_absolute(), f"INTERNAL ERROR: `root` must be absolute but is {root}"
for child in path.iterdir():
- normalized_path = child.resolve().relative_to(root).as_posix()
+ # First ignore files matching .gitignore
+ if gitignore.match_file(child.as_posix()):
+ report.path_ignored(child, "matches the .gitignore file content")
+ continue
+
+ # Then ignore with `exclude` option.
+ try:
+ normalized_path = "/" + child.resolve().relative_to(root).as_posix()
+ except OSError as e:
+ report.path_ignored(child, f"cannot be read because {e}")
+ continue
+
+ except ValueError:
+ if child.is_symlink():
+ report.path_ignored(
+ child, f"is a symbolic link that points outside {root}"
+ )
+ continue
+
+ raise
+
if child.is_dir():
normalized_path += "/"
+
exclude_match = exclude.search(normalized_path)
if exclude_match and exclude_match.group(0):
+ report.path_ignored(child, "matches the --exclude regular expression")
continue
if child.is_dir():
- yield from gen_python_files_in_dir(child, root, include, exclude)
+ yield from gen_python_files_in_dir(
+ child, root, include, exclude, report, gitignore
+ )
elif child.is_file():
include_match = include.search(normalized_path)
yield child
-def find_project_root(srcs: List[str]) -> Path:
+@lru_cache()
+def find_project_root(srcs: Iterable[str]) -> Path:
"""Return a directory containing .git, .hg, or pyproject.toml.
That directory can be one of the directories passed in `srcs` or their
# Append a fake file so `parents` below returns `common_base_dir`, too.
common_base /= "fake-file"
for directory in common_base.parents:
- if (directory / ".git").is_dir():
+ if (directory / ".git").exists():
return directory
if (directory / ".hg").is_dir():
"""Provides a reformatting counter. Can be rendered with `str(report)`."""
check: bool = False
+ diff: bool = False
quiet: bool = False
+ verbose: bool = False
change_count: int = 0
same_count: int = 0
failure_count: int = 0
def done(self, src: Path, changed: Changed) -> None:
"""Increment the counter for successful reformatting. Write out a message."""
if changed is Changed.YES:
- reformatted = "would reformat" if self.check else "reformatted"
- if not self.quiet:
+ reformatted = "would reformat" if self.check or self.diff else "reformatted"
+ if self.verbose or not self.quiet:
out(f"{reformatted} {src}")
self.change_count += 1
else:
- if not self.quiet:
+ if self.verbose:
if changed is Changed.NO:
msg = f"{src} already well formatted, good job."
else:
err(f"error: cannot format {src}: {message}")
self.failure_count += 1
+ def path_ignored(self, path: Path, message: str) -> None:
+ if self.verbose:
+ out(f"{path} ignored: {message}", bold=False)
+
@property
def return_code(self) -> int:
"""Return the exit code that the app should use.
- otherwise return 0.
"""
# According to http://tldp.org/LDP/abs/html/exitcodes.html starting with
- # 126 we have special returncodes reserved by the shell.
+ # 126 we have special return codes reserved by the shell.
if self.failure_count:
return 123
Use `click.unstyle` to remove colors.
"""
- if self.check:
+ if self.check or self.diff:
reformatted = "would be reformatted"
unchanged = "would be left unchanged"
failed = "would fail to reformat"
return ", ".join(report) + "."
+def parse_ast(src: str) -> Union[ast.AST, ast3.AST, ast27.AST]:
+ filename = "<unknown>"
+ if sys.version_info >= (3, 8):
+ # TODO: support Python 4+ ;)
+ for minor_version in range(sys.version_info[1], 4, -1):
+ try:
+ return ast.parse(src, filename, feature_version=(3, minor_version))
+ except SyntaxError:
+ continue
+ else:
+ for feature_version in (7, 6):
+ try:
+ return ast3.parse(src, filename, feature_version=feature_version)
+ except SyntaxError:
+ continue
+
+ return ast27.parse(src)
+
+
+def _fixup_ast_constants(
+ node: Union[ast.AST, ast3.AST, ast27.AST]
+) -> Union[ast.AST, ast3.AST, ast27.AST]:
+ """Map ast nodes deprecated in 3.8 to Constant."""
+ if isinstance(node, (ast.Str, ast3.Str, ast27.Str, ast.Bytes, ast3.Bytes)):
+ return ast.Constant(value=node.s)
+
+ if isinstance(node, (ast.Num, ast3.Num, ast27.Num)):
+ return ast.Constant(value=node.n)
+
+ if isinstance(node, (ast.NameConstant, ast3.NameConstant)):
+ return ast.Constant(value=node.value)
+
+ return node
+
+
def assert_equivalent(src: str, dst: str) -> None:
"""Raise AssertionError if `src` and `dst` aren't equivalent."""
- import ast
- import traceback
-
- def _v(node: ast.AST, depth: int = 0) -> Iterator[str]:
+ def _v(node: Union[ast.AST, ast3.AST, ast27.AST], depth: int = 0) -> Iterator[str]:
"""Simple visitor generating strings to compare ASTs by content."""
+
+ node = _fixup_ast_constants(node)
+
yield f"{' ' * depth}{node.__class__.__name__}("
- for field in sorted(node._fields):
+ for field in sorted(node._fields): # noqa: F402
+ # TypeIgnore has only one field 'lineno' which breaks this comparison
+ type_ignore_classes = (ast3.TypeIgnore, ast27.TypeIgnore)
+ if sys.version_info >= (3, 8):
+ type_ignore_classes += (ast.TypeIgnore,)
+ if isinstance(node, type_ignore_classes):
+ break
+
try:
value = getattr(node, field)
except AttributeError:
if isinstance(value, list):
for item in value:
- if isinstance(item, ast.AST):
+ # Ignore nested tuples within del statements, because we may insert
+ # parentheses and they change the AST.
+ if (
+ field == "targets"
+ and isinstance(node, (ast.Delete, ast3.Delete, ast27.Delete))
+ and isinstance(item, (ast.Tuple, ast3.Tuple, ast27.Tuple))
+ ):
+ for item in item.elts:
+ yield from _v(item, depth + 2)
+
+ elif isinstance(item, (ast.AST, ast3.AST, ast27.AST)):
yield from _v(item, depth + 2)
- elif isinstance(value, ast.AST):
+ elif isinstance(value, (ast.AST, ast3.AST, ast27.AST)):
yield from _v(value, depth + 2)
else:
yield f"{' ' * depth}) # /{node.__class__.__name__}"
try:
- src_ast = ast.parse(src)
+ src_ast = parse_ast(src)
except Exception as exc:
- major, minor = sys.version_info[:2]
raise AssertionError(
- f"cannot use --safe with this file; failed to parse source file "
- f"with Python {major}.{minor}'s builtin AST. Re-run with --fast "
- f"or stop using deprecated Python 2 syntax. AST error message: {exc}"
+ f"cannot use --safe with this file; failed to parse source file. "
+ f"AST error message: {exc}"
)
try:
- dst_ast = ast.parse(dst)
+ dst_ast = parse_ast(dst)
except Exception as exc:
log = dump_to_file("".join(traceback.format_tb(exc.__traceback__)), dst)
raise AssertionError(
f"INTERNAL ERROR: Black produced invalid code: {exc}. "
- f"Please report a bug on https://github.com/ambv/black/issues. "
+ f"Please report a bug on https://github.com/psf/black/issues. "
f"This invalid output might be helpful: {log}"
) from None
raise AssertionError(
f"INTERNAL ERROR: Black produced code that is not equivalent to "
f"the source. "
- f"Please report a bug on https://github.com/ambv/black/issues. "
+ f"Please report a bug on https://github.com/psf/black/issues. "
f"This diff might be helpful: {log}"
) from None
-def assert_stable(
- src: str, dst: str, line_length: int, mode: FileMode = FileMode.AUTO_DETECT
-) -> None:
+def assert_stable(src: str, dst: str, mode: Mode) -> None:
"""Raise AssertionError if `dst` reformats differently the second time."""
- newdst = format_str(dst, line_length=line_length, mode=mode)
+ newdst = format_str(dst, mode=mode)
if dst != newdst:
log = dump_to_file(
diff(src, dst, "source", "first pass"),
raise AssertionError(
f"INTERNAL ERROR: Black produced different code on the second pass "
f"of the formatter. "
- f"Please report a bug on https://github.com/ambv/black/issues. "
+ f"Please report a bug on https://github.com/psf/black/issues. "
f"This diff might be helpful: {log}"
) from None
+@mypyc_attr(patchable=True)
def dump_to_file(*output: str) -> str:
"""Dump `output` to a temporary file. Return path to the file."""
- import tempfile
-
with tempfile.NamedTemporaryFile(
mode="w", prefix="blk_", suffix=".log", delete=False, encoding="utf8"
) as f:
return f.name
+@contextmanager
+def nullcontext() -> Iterator[None]:
+ """Return an empty context manager.
+
+ To be used like `nullcontext` in Python 3.7.
+ """
+ yield
+
+
def diff(a: str, b: str, a_name: str, b_name: str) -> str:
"""Return a unified diff string between strings `a` and `b`."""
import difflib
- a_lines = [line + "\n" for line in a.split("\n")]
- b_lines = [line + "\n" for line in b.split("\n")]
+ a_lines = [line + "\n" for line in a.splitlines()]
+ b_lines = [line + "\n" for line in b.splitlines()]
return "".join(
difflib.unified_diff(a_lines, b_lines, fromfile=a_name, tofile=b_name, n=5)
)
-def cancel(tasks: Iterable[asyncio.Task]) -> None:
+def cancel(tasks: Iterable["asyncio.Task[Any]"]) -> None:
"""asyncio signal handler that cancels all `tasks` and reports to stderr."""
err("Aborted!")
for task in tasks:
task.cancel()
-def shutdown(loop: BaseEventLoop) -> None:
+def shutdown(loop: asyncio.AbstractEventLoop) -> None:
"""Cancel all pending tasks on `loop`, wait for them, and close the loop."""
try:
+ if sys.version_info[:2] >= (3, 7):
+ all_tasks = asyncio.all_tasks
+ else:
+ all_tasks = asyncio.Task.all_tasks
# This part is borrowed from asyncio/runners.py in Python 3.7b2.
- to_cancel = [task for task in asyncio.Task.all_tasks(loop) if not task.done()]
+ to_cancel = [task for task in all_tasks(loop) if not task.done()]
if not to_cancel:
return
return regex.sub(replacement, regex.sub(replacement, original))
+def re_compile_maybe_verbose(regex: str) -> Pattern[str]:
+ """Compile a regular expression string in `regex`.
+
+ If it contains newlines, use verbose mode.
+ """
+ if "\n" in regex:
+ regex = "(?x)" + regex
+ compiled: Pattern[str] = re.compile(regex)
+ return compiled
+
+
def enumerate_reversed(sequence: Sequence[T]) -> Iterator[Tuple[Index, T]]:
"""Like `reversed(enumerate(sequence))` if that were possible."""
index = len(sequence) - 1
if "\n" in leaf.value:
return # Multiline strings, we can't continue.
- comment: Optional[Leaf]
- for comment in line.comments_after(leaf, index):
+ for comment in line.comments_after(leaf):
length += len(comment.value)
yield index, leaf, length
)
+def can_be_split(line: Line) -> bool:
+ """Return False if the line cannot be split *for sure*.
+
+ This is not an exhaustive search but a cheap heuristic that we can use to
+ avoid some unfortunate formattings (mostly around wrapping unsplittable code
+ in unnecessary parentheses).
+ """
+ leaves = line.leaves
+ if len(leaves) < 2:
+ return False
+
+ if leaves[0].type == token.STRING and leaves[1].type == token.DOT:
+ call_count = 0
+ dot_count = 0
+ next = leaves[-1]
+ for leaf in leaves[-2::-1]:
+ if leaf.type in OPENING_BRACKETS:
+ if next.type not in CLOSING_BRACKETS:
+ return False
+
+ call_count += 1
+ elif leaf.type == token.DOT:
+ dot_count += 1
+ elif leaf.type == token.NAME:
+ if not (next.type == token.DOT or next.type in OPENING_BRACKETS):
+ return False
+
+ elif leaf.type not in CLOSING_BRACKETS:
+ return False
+
+ if dot_count > 1 and call_count > 1:
+ return False
+
+ return True
+
+
def can_omit_invisible_parens(line: Line, line_length: int) -> bool:
"""Does `line` have a shape safe to reformat without optional parens around it?
return False
-def get_cache_file(line_length: int, mode: FileMode) -> Path:
- pyi = bool(mode & FileMode.PYI)
- py36 = bool(mode & FileMode.PYTHON36)
- return (
- CACHE_DIR
- / f"cache.{line_length}{'.pyi' if pyi else ''}{'.py36' if py36 else ''}.pickle"
- )
+def get_cache_file(mode: Mode) -> Path:
+ return CACHE_DIR / f"cache.{mode.get_cache_key()}.pickle"
-def read_cache(line_length: int, mode: FileMode) -> Cache:
+def read_cache(mode: Mode) -> Cache:
"""Read the cache if it exists and is well formed.
If it is not well formed, the call to write_cache later should resolve the issue.
"""
- cache_file = get_cache_file(line_length, mode)
+ cache_file = get_cache_file(mode)
if not cache_file.exists():
return {}
with cache_file.open("rb") as fobj:
try:
cache: Cache = pickle.load(fobj)
- except pickle.UnpicklingError:
+ except (pickle.UnpicklingError, ValueError):
return {}
return cache
return stat.st_mtime, stat.st_size
-def filter_cached(
- cache: Cache, sources: Iterable[Path]
-) -> Tuple[List[Path], List[Path]]:
- """Split a list of paths into two.
+def filter_cached(cache: Cache, sources: Iterable[Path]) -> Tuple[Set[Path], Set[Path]]:
+ """Split an iterable of paths in `sources` into two sets.
- The first list contains paths of files that modified on disk or are not in the
- cache. The other list contains paths to non-modified files.
+ The first contains paths of files that modified on disk or are not in the
+ cache. The other contains paths to non-modified files.
"""
- todo, done = [], []
+ todo, done = set(), set()
for src in sources:
src = src.resolve()
if cache.get(src) != get_cache_info(src):
- todo.append(src)
+ todo.add(src)
else:
- done.append(src)
+ done.add(src)
return todo, done
-def write_cache(
- cache: Cache, sources: List[Path], line_length: int, mode: FileMode
-) -> None:
+def write_cache(cache: Cache, sources: Iterable[Path], mode: Mode) -> None:
"""Update the cache file."""
- cache_file = get_cache_file(line_length, mode)
+ cache_file = get_cache_file(mode)
try:
- if not CACHE_DIR.exists():
- CACHE_DIR.mkdir(parents=True)
+ CACHE_DIR.mkdir(parents=True, exist_ok=True)
new_cache = {**cache, **{src.resolve(): get_cache_info(src) for src in sources}}
- with cache_file.open("wb") as fobj:
- pickle.dump(new_cache, fobj, protocol=pickle.HIGHEST_PROTOCOL)
+ with tempfile.NamedTemporaryFile(dir=str(cache_file.parent), delete=False) as f:
+ pickle.dump(new_cache, f, protocol=4)
+ os.replace(f.name, cache_file)
except OSError:
pass
-if __name__ == "__main__":
+def patch_click() -> None:
+ """Make Click not crash.
+
+ On certain misconfigured environments, Python 3 selects the ASCII encoding as the
+ default which restricts paths that it can access during the lifetime of the
+ application. Click refuses to work in this scenario by raising a RuntimeError.
+
+ In case of Black the likelihood that non-ASCII characters are going to be used in
+ file paths is minimal since it's Python source code. Moreover, this crash was
+ spurious on Python 3.7 thanks to PEP 538 and PEP 540.
+ """
+ try:
+ from click import core
+ from click import _unicodefun # type: ignore
+ except ModuleNotFoundError:
+ return
+
+ for module in (core, _unicodefun):
+ if hasattr(module, "_verify_python3_env"):
+ module._verify_python3_env = lambda: None
+
+
+def patched_main() -> None:
+ freeze_support()
+ patch_click()
main()
+
+
+if __name__ == "__main__":
+ patched_main()
projects / etc / vim.git / blobdiff