from asyncio.base_events import BaseEventLoop
from concurrent.futures import Executor, ProcessPoolExecutor
from datetime import datetime
-from enum import Enum, Flag
+from enum import Enum
from functools import lru_cache, partial, wraps
import io
-import keyword
+import itertools
import logging
-from multiprocessing import Manager
+from multiprocessing import Manager, freeze_support
import os
from pathlib import Path
import pickle
import re
import signal
import sys
+import tempfile
import tokenize
from typing import (
Any,
)
from appdirs import user_cache_dir
-from attr import dataclass, Factory
+from attr import dataclass, evolve, Factory
import click
import toml
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
-__version__ = "18.6b4"
+__version__ = "18.9b0"
DEFAULT_LINE_LENGTH = 88
DEFAULT_EXCLUDES = (
- r"/(\.git|\.hg|\.mypy_cache|\.tox|\.venv|_build|buck-out|build|dist)/"
+ r"/(\.eggs|\.git|\.hg|\.mypy_cache|\.nox|\.tox|\.venv|_build|buck-out|build|dist)/"
)
DEFAULT_INCLUDES = r"\.pyi?$"
CACHE_DIR = Path(user_cache_dir("black", version=__version__))
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 WriteBack(Enum):
NO = 0
YES = 1
DIFF = 2
+ CHECK = 3
@classmethod
def from_configuration(cls, *, check: bool, diff: bool) -> "WriteBack":
if check and not diff:
- return cls.NO
+ return cls.CHECK
return cls.DIFF if diff else cls.YES
YES = 2
-class FileMode(Flag):
- AUTO_DETECT = 0
- PYTHON36 = 1
- PYI = 2
- NO_STRING_NORMALIZATION = 4
+class TargetVersion(Enum):
+ PYPY35 = 1
+ CPY27 = 2
+ CPY33 = 3
+ CPY34 = 4
+ CPY35 = 5
+ CPY36 = 6
+ CPY37 = 7
+ CPY38 = 8
+
+ def is_python2(self) -> bool:
+ return self is TargetVersion.CPY27
+
+
+PY36_VERSIONS = {TargetVersion.CPY36, TargetVersion.CPY37, TargetVersion.CPY38}
+
+
+class Feature(Enum):
+ # All string literals are unicode
+ UNICODE_LITERALS = 1
+ F_STRINGS = 2
+ NUMERIC_UNDERSCORES = 3
+ TRAILING_COMMA = 4
+
+
+VERSION_TO_FEATURES: Dict[TargetVersion, Set[Feature]] = {
+ TargetVersion.CPY27: set(),
+ TargetVersion.PYPY35: {Feature.UNICODE_LITERALS, Feature.F_STRINGS},
+ TargetVersion.CPY33: {Feature.UNICODE_LITERALS},
+ TargetVersion.CPY34: {Feature.UNICODE_LITERALS},
+ TargetVersion.CPY35: {Feature.UNICODE_LITERALS, Feature.TRAILING_COMMA},
+ TargetVersion.CPY36: {
+ Feature.UNICODE_LITERALS,
+ Feature.F_STRINGS,
+ Feature.NUMERIC_UNDERSCORES,
+ Feature.TRAILING_COMMA,
+ },
+ TargetVersion.CPY37: {
+ Feature.UNICODE_LITERALS,
+ Feature.F_STRINGS,
+ Feature.NUMERIC_UNDERSCORES,
+ Feature.TRAILING_COMMA,
+ },
+ TargetVersion.CPY38: {
+ Feature.UNICODE_LITERALS,
+ Feature.F_STRINGS,
+ Feature.NUMERIC_UNDERSCORES,
+ Feature.TRAILING_COMMA,
+ },
+}
+
+
+@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)
- @classmethod
- def from_configuration(
- cls, *, py36: bool, pyi: bool, skip_string_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
- return 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 read_pyproject_toml(
pyproject_toml = toml.load(value)
config = pyproject_toml.get("tool", {}).get("black", {})
except (toml.TomlDecodeError, OSError) as e:
- raise click.BadOptionUsage(f"Error reading configuration file: {e}", ctx)
+ raise click.FileError(
+ filename=value, hint=f"Error reading configuration file: {e}"
+ )
if not config:
return None
"--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(
- "--py36",
- is_flag=True,
+ "-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=(
- "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]"
+ "Python versions that should be supported by Black's output. [default: "
+ "per-file auto-detection]"
),
)
@click.option(
def main(
ctx: click.Context,
line_length: int,
+ target_version: List[TargetVersion],
check: bool,
diff: bool,
fast: bool,
pyi: bool,
- py36: bool,
skip_string_normalization: bool,
quiet: bool,
verbose: bool,
) -> 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
+ if target_version:
+ versions = set(target_version)
+ 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 len(sources) == 1:
reformat_one(
src=sources.pop(),
- line_length=line_length,
fast=fast,
write_back=write_back,
mode=mode,
loop.run_until_complete(
schedule_formatting(
sources=sources,
- line_length=line_length,
fast=fast,
write_back=write_back,
mode=mode,
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.
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))
async def schedule_formatting(
sources: Set[Path],
- line_length: int,
fast: bool,
write_back: WriteBack,
mode: FileMode,
"""
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)
+ 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 = {
- 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)
+ 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 = {
+ 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()
+ 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: 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 True, write reformatted code back to stdout.
+ 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`.
"""
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
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 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`.
"""
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 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.
"""
- src_node = lib2to3_parse(src_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
for current_line in lines.visit(src_node):
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):
+ for line in split_line(
+ current_line,
+ line_length=mode.line_length,
+ supports_trailing_commas=supports_feature(versions, Feature.TRAILING_COMMA),
+ ):
dst_contents += str(line)
return dst_contents
]
-def lib2to3_parse(src_txt: str) -> Node:
+def get_grammars(target_versions: Set[TargetVersion]) -> List[Grammar]:
+ if not target_versions:
+ return GRAMMARS
+ elif all(not version.is_python2() for version in target_versions):
+ # Python 2-compatible code, so don't try Python 3 grammar.
+ return [
+ pygram.python_grammar_no_print_statement_no_exec_statement,
+ pygram.python_grammar_no_print_statement,
+ ]
+ else:
+ return [pygram.python_grammar]
+
+
+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":
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)
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
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,
bracket_match: Dict[Tuple[Depth, NodeType], Leaf] = Factory(dict)
delimiters: Dict[LeafID, Priority] = Factory(dict)
previous: Optional[Leaf] = None
- _for_loop_variable: int = 0
- _lambda_arguments: int = 0
+ _for_loop_depths: List[int] = Factory(list)
+ _lambda_argument_depths: List[int] = Factory(list)
def mark(self, leaf: Leaf) -> None:
"""Mark `leaf` with bracket-related metadata. Keep track of delimiters.
"""
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
depth: int = 0
leaves: List[Leaf] = Factory(list)
- comments: List[Tuple[Index, 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)
bracket_tracker: BracketTracker = Factory(BracketTracker)
inside_brackets: bool = False
should_explode: bool = False
self.remove_trailing_comma()
return True
- # Otheriwsse, if the trailing one is the only one, we might mistakenly
+ # Otherwise, 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
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 not self.comments:
- return
-
- if _index == -1:
- for _index, _leaf in enumerate(self.leaves):
- if leaf is _leaf:
- break
-
+ leaf_id = id(self.leaves[-1])
+ if leaf_id not in self.comments:
+ self.comments[leaf_id] = [comment]
else:
- return
+ self.comments[leaf_id].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)
+ # 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]), [])
+ )
+ self.comments.pop(id(self.leaves[-1]), None)
self.leaves.pop()
def is_complex_subscript(self, leaf: Leaf) -> bool:
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"
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 emty body
+ # No blank line between classes with an empty body
newlines = 0
else:
newlines = 1
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)
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
return container
-def is_split_after_delimiter(leaf: Leaf, previous: Leaf = None) -> int:
+def is_split_after_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> int:
"""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) -> int:
+ """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"
@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
@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
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,
+ supports_trailing_commas: bool = False,
) -> 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.
+ If `supports_trailing_commas` is True, splitting may use the TRAILING_COMMA feature.
"""
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
+
+ # 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
+ and not line.should_explode
+ and is_line_short_enough(line, line_length=line_length, line_str=line_str)
):
yield line
return
split_funcs = [left_hand_split]
else:
- def rhs(line: Line, py36: bool = False) -> Iterator[Line]:
+ def rhs(line: Line, supports_trailing_commas: bool = False) -> 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, supports_trailing_commas, 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, supports_trailing_commas)
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, supports_trailing_commas):
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,
+ supports_trailing_commas=supports_trailing_commas,
+ )
)
- 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, supports_trailing_commas: bool = False
+) -> 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] = []
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,
+ supports_trailing_commas: bool = False,
+ 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] = []
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)
- assert opening_bracket and closing_bracket
- body.should_explode = should_explode(body, opening_bracket)
+ 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)
if (
# the body shouldn't be exploded
):
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,
+ supports_trailing_commas=supports_trailing_commas,
+ omit=omit,
+ )
return
except CannotSplit:
)
+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 when expected.
+ if original.is_import:
+ if leaves[-1].type != token.COMMA:
+ leaves.append(Leaf(token.COMMA, ","))
+ # 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, supports_trailing_commas: bool = False
+ ) -> Iterator[Line]:
+ for l in split_func(line, supports_trailing_commas):
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, supports_trailing_commas: bool = False
+) -> 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 `supports_trailing_commas` is True, the split will add trailing commas
+ also in function signatures 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
+ trailing_comma_safe = trailing_comma_safe and supports_trailing_commas
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, supports_trailing_commas: bool = False
+) -> 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_special_comment(leaf: Leaf) -> 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:"))
+ )
+
+
def normalize_prefix(leaf: Leaf, *, inside_brackets: bool) -> None:
"""Leave existing extra newlines if not `inside_brackets`. Remove everything
else.
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.
for index, child in enumerate(list(node.children)):
if check_lpar:
if child.type == syms.atom:
- maybe_make_parens_invisible_in_atom(child)
+ if maybe_make_parens_invisible_in_atom(child):
+ lpar = Leaf(token.LPAR, "")
+ rpar = Leaf(token.RPAR, "")
+ index = child.remove() or 0
+ node.insert_child(index, Node(syms.atom, [lpar, child, rpar]))
elif is_one_tuple(child):
# wrap child in visible parentheses
lpar = Leaf(token.LPAR, "(")
def maybe_make_parens_invisible_in_atom(node: LN) -> bool:
- """If it's safe, make the parens in the atom `node` invisible, recursively."""
+ """If it's safe, make the parens in the atom `node` invisible, recursively.
+
+ Returns whether the node should itself be wrapped in invisible parentheses.
+
+ """
if (
node.type != syms.atom
or is_empty_tuple(node)
last.value = "" # type: ignore
if len(node.children) > 1:
maybe_make_parens_invisible_in_atom(node.children[1])
- return True
+ return False
- return False
+ return True
def is_empty_tuple(node: LN) -> bool:
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
+ - f-strings;
+ - underscores in numeric literals; and
- trailing commas after * or ** in function signatures and calls.
"""
+ 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 in {syms.typedargslist, syms.arglist}
):
for ch in n.children:
if ch.type in STARS:
- return True
+ features.add(Feature.TRAILING_COMMA)
if ch.type == syms.argument:
for argch in ch.children:
if argch.type in STARS:
- return True
+ features.add(Feature.TRAILING_COMMA)
- 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]]:
length = 4 * line.depth
opening_bracket = None
closing_bracket = None
- optional_brackets: Set[LeafID] = set()
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]:
- 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
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)
+ and isinstance(item, ast.Tuple)
+ ):
+ for item in item.elts:
+ yield from _v(item, depth + 2)
+ elif isinstance(item, ast.AST):
yield from _v(item, depth + 2)
elif isinstance(value, ast.AST):
) 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"),
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
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
module._verify_python3_env = lambda: None
-if __name__ == "__main__":
+def patched_main() -> None:
+ freeze_support()
patch_click()
main()
+
+
+if __name__ == "__main__":
+ patched_main()