+import ast
import asyncio
-from asyncio.base_events import BaseEventLoop
from concurrent.futures import Executor, ProcessPoolExecutor
+from contextlib import contextmanager
from datetime import datetime
-from enum import Enum, Flag
+from enum import Enum
from functools import lru_cache, partial, wraps
import io
import itertools
-import keyword
import logging
from multiprocessing import Manager, freeze_support
import os
from pathlib import Path
import pickle
-import re
+import regex as re
import signal
import sys
+import tempfile
import tokenize
+import traceback
from typing import (
Any,
Callable,
)
from appdirs import user_cache_dir
-from attr import dataclass, Factory
+from attr import dataclass, evolve, Factory
import click
import toml
+from typed_ast import ast3, ast27
# 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 _version import version as __version__
-__version__ = "18.9b0"
DEFAULT_LINE_LENGTH = 88
DEFAULT_EXCLUDES = (
r"/(\.eggs|\.git|\.hg|\.mypy_cache|\.nox|\.tox|\.venv|_build|buck-out|build|dist)/"
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]
YES = 2
-class FileMode(Flag):
- AUTO_DETECT = 0
- PYTHON36 = 1
- PYI = 2
- NO_STRING_NORMALIZATION = 4
- NO_NUMERIC_UNDERSCORE_NORMALIZATION = 8
+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,
+ },
+}
- @classmethod
- def from_configuration(
- cls,
- *,
- py36: bool,
- pyi: bool,
- skip_string_normalization: bool,
- skip_numeric_underscore_normalization: bool,
- ) -> "FileMode":
- mode = cls.AUTO_DETECT
- if py36:
- mode |= cls.PYTHON36
- if pyi:
- mode |= cls.PYI
- if skip_string_normalization:
- mode |= cls.NO_STRING_NORMALIZATION
- if skip_numeric_underscore_normalization:
- mode |= cls.NO_NUMERIC_UNDERSCORE_NORMALIZATION
- return mode
+
+@dataclass
+class FileMode:
+ target_versions: Set[TargetVersion] = Factory(set)
+ line_length: int = DEFAULT_LINE_LENGTH
+ string_normalization: bool = True
+ is_pyi: bool = False
+
+ 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)
+
+
+def supports_feature(target_versions: Set[TargetVersion], feature: Feature) -> bool:
+ return all(feature in VERSION_TO_FEATURES[version] for version in target_versions)
def read_pyproject_toml(
@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",
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=lambda c, p, v: [TargetVersion[val.upper()] for val in v],
+ 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(
is_flag=True,
help="Don't normalize string quotes or prefixes.",
)
-@click.option(
- "-N",
- "--skip-numeric-underscore-normalization",
- is_flag=True,
- help="Don't normalize underscores in numeric literals.",
-)
@click.option(
"--check",
is_flag=True,
"--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.pass_context
def main(
ctx: click.Context,
+ code: Optional[str],
line_length: int,
+ target_version: List[TargetVersion],
check: bool,
diff: bool,
fast: bool,
pyi: bool,
py36: bool,
skip_string_normalization: bool,
- skip_numeric_underscore_normalization: bool,
quiet: bool,
verbose: bool,
include: str,
) -> None:
"""The uncompromising code formatter."""
write_back = WriteBack.from_configuration(check=check, diff=diff)
- mode = FileMode.from_configuration(
- py36=py36,
- pyi=pyi,
- skip_string_normalization=skip_string_normalization,
- skip_numeric_underscore_normalization=skip_numeric_underscore_normalization,
+ if target_version:
+ if py36:
+ err(f"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 = FileMode(
+ 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_maybe_verbose(include)
except re.error:
report = Report(check=check, 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():
err(f"invalid path: {s}")
if len(sources) == 0:
if verbose or not quiet:
- out("No paths given. Nothing to do 😴")
+ out("No Python files are present to be formatted. Nothing to do 😴")
ctx.exit(0)
if len(sources) == 1:
reformat_one(
src=sources.pop(),
- line_length=line_length,
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)
+ reformat_many(
+ sources=sources, fast=fast, write_back=write_back, mode=mode, report=report
+ )
+
if verbose or not quiet:
- bang = "💥 💔 💥" if report.return_code else "✨ 🍰 ✨"
- out(f"All done! {bang}")
+ 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: FileMode, 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 is WriteBack.YES and changed is not Changed.CACHED) or (
write_back is WriteBack.CHECK and changed is Changed.NO
):
- write_cache(cache, [src], line_length, mode)
+ 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: FileMode,
+ 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: Set[Path],
- line_length: int,
fast: bool,
write_back: WriteBack,
mode: FileMode,
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 sorted(cached):
report.done(src, Changed.CACHED)
manager = Manager()
lock = manager.Lock()
tasks = {
- loop.run_in_executor(
- executor,
- format_file_in_place,
- src,
- line_length,
- fast,
- write_back,
- mode,
- lock,
+ asyncio.ensure_future(
+ loop.run_in_executor(
+ executor, format_file_in_place, src, fast, mode, write_back, lock
+ )
): src
for src in sorted(sources)
}
- pending: Iterable[asyncio.Task] = tasks.keys()
+ pending: Iterable[asyncio.Future] = tasks.keys()
try:
loop.add_signal_handler(signal.SIGINT, cancel, pending)
loop.add_signal_handler(signal.SIGTERM, cancel, pending)
if cancelled:
await asyncio.gather(*cancelled, loop=loop, return_exceptions=True)
if sources_to_cache:
- write_cache(cache, sources_to_cache, line_length, mode)
+ write_cache(cache, sources_to_cache, mode)
def format_file_in_place(
src: Path,
- line_length: int,
fast: bool,
+ mode: FileMode,
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 DIFF, write a diff to stdout. If it is YES, write reformatted
code to the file.
- `line_length` and `fast` options are passed to :func:`format_file_contents`.
+ `mode` and `fast` options are passed to :func:`format_file_contents`.
"""
if src.suffix == ".pyi":
- mode |= FileMode.PYI
+ mode = evolve(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
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:
+
+ with lock or nullcontext():
f = io.TextIOWrapper(
sys.stdout.buffer,
encoding=encoding,
)
f.write(diff_contents)
f.detach()
- finally:
- if lock:
- lock.release()
+
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: FileMode
) -> bool:
"""Format file on stdin. Return True if changed.
If `write_back` is YES, write reformatted code back to stdout. If it is DIFF,
- write a diff to stdout.
- `line_length`, `fast`, `is_pyi`, and `force_py36` arguments are passed to
+ write a diff to stdout. The `mode` argument is passed to
:func:`format_file_contents`.
"""
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:
def format_file_contents(
- src_contents: str,
- *,
- line_length: int,
- fast: bool,
- mode: FileMode = FileMode.AUTO_DETECT,
+ src_contents: str, *, fast: bool, mode: FileMode
) -> 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: FileMode) -> 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.
"""
- src_node = lib2to3_parse(src_contents.lstrip())
- 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,
- allow_underscores=py36
- and not bool(mode & FileMode.NO_NUMERIC_UNDERSCORE_NORMALIZATION),
+ 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))
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))
+ 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 tiow.read(), encoding, newline
-GRAMMARS = [
- pygram.python_grammar_no_print_statement_no_exec_statement,
- pygram.python_grammar_no_print_statement,
- pygram.python_grammar,
-]
+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,
+ ]
+ elif 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,
+ ]
+ else:
+ # 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 # noqa: B950
+ )
+ 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."""
if src_txt[-1:] != "\n":
src_txt += "\n"
- for grammar in GRAMMARS:
+
+ for grammar in get_grammars(set(target_versions)):
drv = driver.Driver(grammar, pytree.convert)
try:
result = drv.parse_string(src_txt, True)
list(v.visit(code))
-KEYWORDS = set(keyword.kwlist)
WHITESPACE = {token.DEDENT, token.INDENT, token.NEWLINE}
-FLOW_CONTROL = {"return", "raise", "break", "continue"}
STATEMENT = {
syms.if_stmt,
syms.while_stmt,
token.DOUBLESTAR,
}
STARS = {token.STAR, token.DOUBLESTAR}
+VARARGS_SPECIALS = STARS | {token.SLASH}
VARARGS_PARENTS = {
syms.arglist,
syms.argument, # double star in arglist
"""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.
depth: int = 0
leaves: List[Leaf] = Factory(list)
- # The LeafID keys of comments must remain ordered by the corresponding leaf's index
- # in leaves
- comments: Dict[LeafID, List[Leaf]] = Factory(dict)
+ comments: Dict[LeafID, List[Leaf]] = Factory(dict) # keys ordered like `leaves`
bracket_tracker: BracketTracker = Factory(BracketTracker)
inside_brackets: bool = False
should_explode: bool = False
if leaf.type == STANDALONE_COMMENT:
if leaf.bracket_depth <= depth_limit:
return True
+ return False
+
+ 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
+
+ # 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 leaf_id not in ignored_ids or comment_seen:
+ return True
+
+ comment_seen = True
+
+ return False
+
+ def contains_unsplittable_type_ignore(self) -> bool:
+ if not self.leaves:
+ return False
+
+ # 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.
+
+ # Like in the type comment check above, we need to skip a black added
+ # trailing comma or invisible paren, since it will be the original leaf
+ # before it that has the original line number.
+ last_idx = -1
+ last_leaf = self.leaves[-1]
+ if len(self.leaves) > 2 and (
+ last_leaf.type == token.COMMA
+ or (last_leaf.type == token.RPAR and not last_leaf.value)
+ ):
+ last_idx = -2
+
+ if self.leaves[0].lineno == self.leaves[last_idx].lineno:
+ for node in self.leaves[last_idx:]:
+ for comment in self.comments.get(id(node), []):
+ if is_type_comment(comment, " ignore"):
+ return True
return False
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:
+ if leaf.parent and leaf.parent.type in {
+ syms.arglist,
+ syms.typedargslist,
+ }:
commas += 1
break
comment.prefix = ""
return False
- else:
- leaf_id = id(self.leaves[-1])
- if leaf_id not in self.comments:
- self.comments[leaf_id] = [comment]
- else:
- self.comments[leaf_id].append(comment)
- return True
+ 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
def comments_after(self, leaf: Leaf) -> List[Leaf]:
"""Generate comments that should appear directly after `leaf`."""
def remove_trailing_comma(self) -> None:
"""Remove the trailing comma and moves the comments attached to it."""
- # Remember, the LeafID keys of self.comments are ordered by the
- # corresponding leaf's index in self.leaves
- # If id(self.leaves[-2]) is in self.comments, the order doesn't change.
- # Otherwise, we insert it into self.comments, and it becomes the last entry.
- # However, since we delete id(self.leaves[-1]) from self.comments, the invariant
- # is maintained
- self.comments.setdefault(id(self.leaves[-2]), []).extend(
- self.comments.get(id(self.leaves[-1]), [])
+ 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
)
- self.comments.pop(id(self.leaves[-1]), None)
- self.leaves.pop()
def is_complex_subscript(self, leaf: Leaf) -> bool:
"""Return True iff `leaf` is part of a slice with non-trivial exprs."""
lines (two on module-level).
"""
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
normalize_strings: bool = True
current_line: Line = Factory(Line)
remove_u_prefix: bool = False
- allow_underscores: bool = False
def line(self, indent: int = 0) -> Iterator[Line]:
"""Generate a line.
normalize_string_prefix(node, remove_u_prefix=self.remove_u_prefix)
normalize_string_quotes(node)
if node.type == token.NUMBER:
- normalize_numeric_literal(node, self.allow_underscores)
+ normalize_numeric_literal(node)
if node.type not in WHITESPACE:
self.current_line.append(node)
yield from super().visit_default(node)
+ def visit_atom(self, node: Node) -> Iterator[Line]:
+ # Always make parentheses invisible around a single node, because it should
+ # not be needed (except in the case of yield, where removing the parentheses
+ # produces a SyntaxError).
+ if (
+ len(node.children) == 3
+ and isinstance(node.children[0], Leaf)
+ and node.children[0].type == token.LPAR
+ and isinstance(node.children[2], Leaf)
+ and node.children[2].type == token.RPAR
+ and isinstance(node.children[1], Leaf)
+ and not (
+ node.children[1].type == token.NAME
+ and node.children[1].value == "yield"
+ )
+ ):
+ node.children[0].value = ""
+ node.children[2].value = ""
+ yield from super().visit_default(node)
+
+ def visit_factor(self, node: Node) -> Iterator[Line]:
+ """Force parentheses between a unary op and a binary power:
+
+ -2 ** 8 -> -(2 ** 8)
+ """
+ child = node.children[1]
+ if child.type == syms.power and len(child.children) == 3:
+ lpar = Leaf(token.LPAR, "(")
+ rpar = Leaf(token.RPAR, ")")
+ index = child.remove() or 0
+ node.insert_child(index, Node(syms.atom, [lpar, child, rpar]))
+ yield from self.visit_default(node)
+
def visit_INDENT(self, node: Node) -> Iterator[Line]:
"""Increase indentation level, maybe yield a line."""
# In blib2to3 INDENT never holds comments.
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:
return container
-def is_split_after_delimiter(leaf: Leaf, previous: Optional[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: Optional[Leaf] = None) -> int:
+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
consumed = 0
nlines = 0
+ 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 not is_endmarker:
+ if index == ignored_lines and not is_endmarker:
comment_type = token.COMMENT # simple trailing comment
else:
comment_type = STANDALONE_COMMENT
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 line.is_comment:
yield line
line_str = str(line).strip("\n")
- # we don't want to split special comments like type annotations
- # https://github.com/python/typing/issues/186
- has_special_comment = False
- for leaf in line.leaves:
- for comment in line.comments_after(leaf):
- if leaf.type == token.COMMA and is_special_comment(comment):
- has_special_comment = True
-
if (
- not has_special_comment
+ not line.contains_uncollapsable_type_comments()
and not line.should_explode
- and is_line_short_enough(line, line_length=line_length, line_str=line_str)
+ 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)
+ yield from right_hand_split(line, line_length, 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:
continue
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.
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.
):
omit = {id(closing_bracket), *omit}
try:
- yield from right_hand_split(line, line_length, py36=py36, omit=omit)
+ yield from right_hand_split(line, line_length, features=features, omit=omit)
return
except CannotSplit:
if leaves:
# Since body is a new indent level, remove spurious leading whitespace.
normalize_prefix(leaves[0], inside_brackets=True)
- # Ensure a trailing comma when expected.
- if original.is_import:
- if leaves[-1].type != token.COMMA:
- leaves.append(Leaf(token.COMMA, ","))
+ # Ensure a trailing comma for imports and standalone function arguments, but
+ # be careful not to add one after any comments.
+ no_commas = original.is_def 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
+ elif leaves[i].type == token.COMMA:
+ break
+ else:
+ leaves.insert(i + 1, Leaf(token.COMMA, ","))
+ break
# Populate the line
for leaf in leaves:
result.append(leaf, preformatted=True)
"""
@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]
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")
)
-def is_special_comment(leaf: Leaf) -> bool:
+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 bool(
- (t == token.COMMENT or t == STANDALONE_COMMENT) and (v.startswith("# type:"))
+ return t in {token.COMMENT, t == STANDALONE_COMMENT} and v.startswith(
+ "# type:" + suffix
)
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 "f" in prefix.casefold():
- matches = re.findall(r"[^{]\{(.*?)\}[^}]", new_body)
+ 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
leaf.value = f"{prefix}{new_quote}{new_body}{new_quote}"
-def normalize_numeric_literal(leaf: Leaf, allow_underscores: bool) -> None:
+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), and long number literals are split using underscores.
+ in Python 2 long literals).
"""
text = leaf.value.lower()
if text.startswith(("0o", "0b")):
sign = "-"
elif after.startswith("+"):
after = after[1:]
- before = format_float_or_int_string(before, allow_underscores)
- after = format_int_string(after, allow_underscores)
+ before = format_float_or_int_string(before)
text = f"{before}e{sign}{after}"
elif text.endswith(("j", "l")):
number = 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, allow_underscores)}{suffix}"
+ text = f"{format_float_or_int_string(number)}{suffix}"
else:
- text = format_float_or_int_string(text, allow_underscores)
+ text = format_float_or_int_string(text)
leaf.value = text
-def format_float_or_int_string(text: str, allow_underscores: bool) -> str:
+def format_float_or_int_string(text: str) -> str:
"""Formats a float string like "1.0"."""
if "." not in text:
- return format_int_string(text, allow_underscores)
-
- before, after = text.split(".")
- before = format_int_string(before, allow_underscores) if before else "0"
- if after:
- after = format_int_string(after, allow_underscores, count_from_end=False)
- else:
- after = "0"
- return f"{before}.{after}"
-
-
-def format_int_string(
- text: str, allow_underscores: bool, count_from_end: bool = True
-) -> str:
- """Normalizes underscores in a string to e.g. 1_000_000.
-
- Input must be a string of digits and optional underscores.
- If count_from_end is False, we add underscores after groups of three digits
- counting from the beginning instead of the end of the strings. This is used
- for the fractional part of float literals.
- """
- if not allow_underscores:
return text
- text = text.replace("_", "")
- if len(text) <= 5:
- # No underscores for numbers <= 5 digits long.
- return text
-
- if count_from_end:
- # Avoid removing leading zeros, which are important if we're formatting
- # part of a number like "0.001".
- return format(int("1" + text), "3_")[1:].lstrip("_")
- else:
- return "_".join(text[i : i + 3] for i in range(0, len(text), 3))
+ 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
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:
- if maybe_make_parens_invisible_in_atom(child):
+ # Determines if the underlying atom should be surrounded with
+ # invisible params - also makes parens invisible recursively
+ # within the atom and removes repeated invisible parens within
+ # the atom
+ should_surround_with_parens = maybe_make_parens_invisible_in_atom(
+ child, parent=node
+ )
+
+ if should_surround_with_parens:
lpar = Leaf(token.LPAR, "")
rpar = Leaf(token.RPAR, "")
index = child.remove() or 0
lpar = Leaf(token.LPAR, "")
rpar = Leaf(token.RPAR, "")
index = child.remove() or 0
- node.insert_child(index, Node(syms.atom, [lpar, child, rpar]))
+ prefix = child.prefix
+ child.prefix = ""
+ new_child = Node(syms.atom, [lpar, child, rpar])
+ new_child.prefix = prefix
+ node.insert_child(index, new_child)
check_lpar = isinstance(child, Leaf) and child.value in parens_after
container = container.next_sibling
-def maybe_make_parens_invisible_in_atom(node: LN) -> bool:
+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.
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])
+ maybe_make_parens_invisible_in_atom(middle, parent=parent)
+
+ 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:
"""Return True if `node` holds an empty tuple."""
return (
)
+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 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 = "("
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;
- - underscores in numeric literals; and
- - trailing commas after * or ** in function signatures and calls.
+ - 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
- return True
+ 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]]:
elif child.type == syms.import_as_names:
yield from get_imports_from_children(child.children)
else:
- assert False, "Invalid syntax parsing imports"
+ raise AssertionError("Invalid syntax parsing imports")
for child in node.children:
if child.type != syms.simple_stmt:
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."""
+ # casts are required until this is released:
+ # https://github.com/python/typeshed/pull/3142
+ if isinstance(node, (ast.Str, ast3.Str, ast27.Str, ast.Bytes, ast3.Bytes)):
+ return cast(ast.AST, ast.Constant(value=node.s))
+ elif isinstance(node, (ast.Num, ast3.Num, ast27.Num)):
+ return cast(ast.AST, ast.Constant(value=node.n))
+ elif isinstance(node, (ast.NameConstant, ast3.NameConstant)):
+ return cast(ast.AST, 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):
+ # 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: FileMode) -> 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
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 context manager that does nothing.
+ Similar to `nullcontext` from 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
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
"""
if "\n" in regex:
regex = "(?x)" + regex
- return re.compile(regex)
+ compiled: Pattern[str] = re.compile(regex)
+ return compiled
def enumerate_reversed(sequence: Sequence[T]) -> Iterator[Tuple[Index, T]]:
if "\n" in leaf.value:
return # Multiline strings, we can't continue.
- comment: Optional[Leaf]
for comment in line.comments_after(leaf):
length += len(comment.value)
return False
-def get_cache_file(line_length: int, mode: FileMode) -> Path:
- return CACHE_DIR / f"cache.{line_length}.{mode.value}.pickle"
+def get_cache_file(mode: FileMode) -> Path:
+ return CACHE_DIR / f"cache.{mode.get_cache_key()}.pickle"
-def read_cache(line_length: int, mode: FileMode) -> Cache:
+def read_cache(mode: FileMode) -> 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 {}
return todo, done
-def write_cache(
- cache: Cache, sources: Iterable[Path], line_length: int, mode: FileMode
-) -> None:
+def write_cache(cache: Cache, sources: Iterable[Path], mode: FileMode) -> 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=pickle.HIGHEST_PROTOCOL)
+ os.replace(f.name, cache_file)
except OSError:
pass
projects / etc / vim.git / blobdiff