-#!/usr/bin/env python3
-
import asyncio
import pickle
from asyncio.base_events import BaseEventLoop
List,
Optional,
Pattern,
+ Sequence,
Set,
Tuple,
Type,
from blib2to3.pgen2 import driver, token
from blib2to3.pgen2.parse import ParseError
-__version__ = "18.4a2"
+
+__version__ = "18.4a6"
DEFAULT_LINE_LENGTH = 88
+
# types
syms = pygram.python_symbols
FileContent = str
self.consumed = consumed
def trim_prefix(self, leaf: Leaf) -> None:
- leaf.prefix = leaf.prefix[self.consumed:]
+ leaf.prefix = leaf.prefix[self.consumed :]
def leaf_from_consumed(self, leaf: Leaf) -> Leaf:
"""Returns a new Leaf from the consumed part of the prefix."""
- unformatted_prefix = leaf.prefix[:self.consumed]
+ unformatted_prefix = leaf.prefix[: self.consumed]
return Leaf(token.NEWLINE, unformatted_prefix)
write_back = WriteBack.YES
report = Report(check=check, quiet=quiet)
if len(sources) == 0:
+ out("No paths given. Nothing to do 😴")
ctx.exit(0)
return
)
):
changed = Changed.YES
- if write_back != WriteBack.DIFF and changed is not Changed.NO:
+ if write_back == WriteBack.YES and changed is not Changed.NO:
write_cache(cache, [src], line_length)
report.done(src, changed)
except Exception as exc:
if cancelled:
await asyncio.gather(*cancelled, loop=loop, return_exceptions=True)
- if write_back != WriteBack.DIFF and formatted:
+ if write_back == WriteBack.YES and formatted:
write_cache(cache, formatted, line_length)
"""
src_node = lib2to3_parse(src_contents)
dst_contents = ""
- lines = LineGenerator()
- elt = EmptyLineTracker()
+ future_imports = get_future_imports(src_node)
py36 = is_python36(src_node)
+ lines = LineGenerator(remove_u_prefix=py36 or "unicode_literals" in future_imports)
+ elt = EmptyLineTracker()
empty_line = Line()
after = 0
for current_line in lines.visit(src_node):
token.GREATEREQUAL,
}
MATH_OPERATORS = {
+ token.VBAR,
+ token.CIRCUMFLEX,
+ token.AMPER,
+ token.LEFTSHIFT,
+ token.RIGHTSHIFT,
token.PLUS,
token.MINUS,
token.STAR,
token.SLASH,
- token.VBAR,
- token.AMPER,
+ token.DOUBLESLASH,
token.PERCENT,
- token.CIRCUMFLEX,
+ token.AT,
token.TILDE,
- token.LEFTSHIFT,
- token.RIGHTSHIFT,
token.DOUBLESTAR,
- token.DOUBLESLASH,
}
STARS = {token.STAR, token.DOUBLESTAR}
VARARGS_PARENTS = {
syms.listmaker,
syms.testlist_gexp,
}
+TEST_DESCENDANTS = {
+ syms.test,
+ syms.lambdef,
+ syms.or_test,
+ syms.and_test,
+ syms.not_test,
+ syms.comparison,
+ syms.star_expr,
+ syms.expr,
+ syms.xor_expr,
+ syms.and_expr,
+ syms.shift_expr,
+ syms.arith_expr,
+ syms.trailer,
+ syms.term,
+ syms.power,
+}
+ASSIGNMENTS = {
+ "=",
+ "+=",
+ "-=",
+ "*=",
+ "@=",
+ "/=",
+ "%=",
+ "&=",
+ "|=",
+ "^=",
+ "<<=",
+ ">>=",
+ "**=",
+ "//=",
+}
COMPREHENSION_PRIORITY = 20
-COMMA_PRIORITY = 10
-TERNARY_PRIORITY = 7
-LOGIC_PRIORITY = 5
-STRING_PRIORITY = 4
-COMPARATOR_PRIORITY = 3
-MATH_PRIORITY = 1
+COMMA_PRIORITY = 18
+TERNARY_PRIORITY = 16
+LOGIC_PRIORITY = 14
+STRING_PRIORITY = 12
+COMPARATOR_PRIORITY = 10
+MATH_PRIORITIES = {
+ token.VBAR: 8,
+ token.CIRCUMFLEX: 7,
+ token.AMPER: 6,
+ token.LEFTSHIFT: 5,
+ token.RIGHTSHIFT: 5,
+ token.PLUS: 4,
+ token.MINUS: 4,
+ token.STAR: 3,
+ token.SLASH: 3,
+ token.DOUBLESLASH: 3,
+ token.PERCENT: 3,
+ token.AT: 3,
+ token.TILDE: 2,
+ token.DOUBLESTAR: 1,
+}
@dataclass
bracket_match: Dict[Tuple[Depth, NodeType], Leaf] = Factory(dict)
delimiters: Dict[LeafID, Priority] = Factory(dict)
previous: Optional[Leaf] = None
- _for_loop_variable: bool = False
- _lambda_arguments: bool = False
+ _for_loop_variable: int = 0
+ _lambda_arguments: int = 0
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 = True
+ self._for_loop_variable += 1
return True
return False
"""See `maybe_increment_for_loop_variable` above for explanation."""
if self._for_loop_variable and leaf.type == token.NAME and leaf.value == "in":
self.depth -= 1
- self._for_loop_variable = False
+ self._for_loop_variable -= 1
return True
return False
"""
if leaf.type == token.NAME and leaf.value == "lambda":
self.depth += 1
- self._lambda_arguments = True
+ self._lambda_arguments += 1
return True
return False
"""See `maybe_increment_lambda_arguments` above for explanation."""
if self._lambda_arguments and leaf.type == token.COLON:
self.depth -= 1
- self._lambda_arguments = False
+ self._lambda_arguments -= 1
return True
return False
+ def get_open_lsqb(self) -> Optional[Leaf]:
+ """Return the most recent opening square bracket (if any)."""
+ return self.bracket_match.get((self.depth - 1, token.RSQB))
+
@dataclass
class Line:
if not has_value:
return
+ if token.COLON == leaf.type and self.is_class_paren_empty:
+ del self.leaves[-2:]
if self.leaves and not preformatted:
# Note: at this point leaf.prefix should be empty except for
# imports, for which we only preserve newlines.
- leaf.prefix += whitespace(leaf)
+ leaf.prefix += whitespace(
+ leaf, complex_subscript=self.is_complex_subscript(leaf)
+ )
if self.inside_brackets or not preformatted:
self.bracket_tracker.mark(leaf)
self.maybe_remove_trailing_comma(leaf)
-
if not self.append_comment(leaf):
self.leaves.append(leaf)
and self.leaves[0].value == "yield"
)
+ @property
+ def is_class_paren_empty(self) -> bool:
+ """Is this a class with no base classes but using parentheses?
+
+ Those are unnecessary and should be removed.
+ """
+ return (
+ bool(self)
+ and len(self.leaves) == 4
+ and self.is_class
+ and self.leaves[2].type == token.LPAR
+ and self.leaves[2].value == "("
+ and self.leaves[3].type == token.RPAR
+ and self.leaves[3].value == ")"
+ )
+
def contains_standalone_comments(self, depth_limit: int = sys.maxsize) -> bool:
"""If so, needs to be split before emitting."""
for leaf in self.leaves:
self.remove_trailing_comma()
return True
- # For parens let's check if it's safe to remove the comma. If the
- # trailing one is the only one, we might mistakenly change a tuple
- # into a different type by removing the comma.
+ # For parens let's check if it's safe to remove the comma.
+ # Imports are always safe.
+ if self.is_import:
+ self.remove_trailing_comma()
+ return True
+
+ # Otheriwsse, if the trailing one is the only one, we might mistakenly
+ # change a tuple into a different type by removing the comma.
depth = closing.bracket_depth + 1
commas = 0
opening = closing.opening_bracket
else:
return False
- for leaf in self.leaves[_opening_index + 1:]:
+ for leaf in self.leaves[_opening_index + 1 :]:
if leaf is closing:
break
self.comments.append((after, comment))
return True
- def comments_after(self, leaf: Leaf) -> Iterator[Leaf]:
- """Generate comments that should appear directly after `leaf`."""
- for _leaf_index, _leaf in enumerate(self.leaves):
- if leaf is _leaf:
- break
+ def comments_after(self, leaf: Leaf, _index: int = -1) -> Iterator[Leaf]:
+ """Generate comments that should appear directly after `leaf`.
- else:
- return
+ Provide a non-negative leaf `_index` to speed up the function.
+ """
+ if _index == -1:
+ for _index, _leaf in enumerate(self.leaves):
+ if leaf is _leaf:
+ break
+
+ else:
+ return
for index, comment_after in self.comments:
- if _leaf_index == index:
+ if _index == index:
yield comment_after
def remove_trailing_comma(self) -> None:
self.comments[i] = (comma_index - 1, comment)
self.leaves.pop()
+ def is_complex_subscript(self, leaf: Leaf) -> bool:
+ """Return True iff `leaf` is part of a slice with non-trivial exprs."""
+ open_lsqb = (
+ leaf if leaf.type == token.LSQB else self.bracket_tracker.get_open_lsqb()
+ )
+ if open_lsqb is None:
+ return False
+
+ subscript_start = open_lsqb.next_sibling
+ if (
+ isinstance(subscript_start, Node)
+ and subscript_start.type == syms.subscriptlist
+ ):
+ subscript_start = child_towards(subscript_start, leaf)
+ return (
+ subscript_start is not None
+ and any(n.type in TEST_DESCENDANTS for n in subscript_start.pre_order())
+ )
+
def __str__(self) -> str:
"""Render the line."""
if not self:
in ways that will no longer stringify to valid Python code on the tree.
"""
current_line: Line = Factory(Line)
+ remove_u_prefix: bool = False
def line(self, indent: int = 0, type: Type[Line] = Line) -> Iterator[Line]:
"""Generate a line.
else:
normalize_prefix(node, inside_brackets=any_open_brackets)
if node.type == token.STRING:
+ normalize_string_prefix(node, remove_u_prefix=self.remove_u_prefix)
normalize_string_quotes(node)
if node.type not in WHITESPACE:
self.current_line.append(node)
"""Visit a statement.
This implementation is shared for `if`, `while`, `for`, `try`, `except`,
- `def`, `with`, `class`, and `assert`.
+ `def`, `with`, `class`, `assert` and assignments.
The relevant Python language `keywords` for a given statement will be
NAME leaves within it. This methods puts those on a separate line.
- `parens` holds pairs of nodes where invisible parentheses should be put.
- Keys hold nodes after which opening parentheses should be put, values
- hold nodes before which closing parentheses should be put.
+ `parens` holds a set of string leaf values immeditely after which
+ invisible parens should be put.
"""
normalize_invisible_parens(node, parens_after=parens)
for child in node.children:
v = self.visit_stmt
Ø: Set[str] = set()
self.visit_assert_stmt = partial(v, keywords={"assert"}, parens={"assert", ","})
- self.visit_if_stmt = partial(v, keywords={"if", "else", "elif"}, parens={"if"})
+ self.visit_if_stmt = partial(
+ v, keywords={"if", "else", "elif"}, parens={"if", "elif"}
+ )
self.visit_while_stmt = partial(v, keywords={"while", "else"}, parens={"while"})
self.visit_for_stmt = partial(v, keywords={"for", "else"}, parens={"for", "in"})
self.visit_try_stmt = partial(
self.visit_with_stmt = partial(v, keywords={"with"}, parens=Ø)
self.visit_funcdef = partial(v, keywords={"def"}, parens=Ø)
self.visit_classdef = partial(v, keywords={"class"}, parens=Ø)
+ self.visit_expr_stmt = partial(v, keywords=Ø, parens=ASSIGNMENTS)
+ self.visit_return_stmt = partial(v, keywords={"return"}, parens={"return"})
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) -> str: # noqa C901
- """Return whitespace prefix if needed for the given `leaf`."""
+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
+ which has non-trivial arguments, like arithmetic expressions or function calls.
+ """
NO = ""
SPACE = " "
DOUBLESPACE = " "
return DOUBLESPACE
assert p is not None, f"INTERNAL ERROR: hand-made leaf without parent: {leaf!r}"
- if t == token.COLON and p.type not in {syms.subscript, syms.subscriptlist}:
+ if (
+ t == token.COLON
+ and p.type not in {syms.subscript, syms.subscriptlist, syms.sliceop}
+ ):
return NO
prev = leaf.prev_sibling
return NO
if t == token.COLON:
- return SPACE if prevp.type == token.COMMA else NO
+ if prevp.type == token.COLON:
+ return NO
+
+ elif prevp.type != token.COMMA and not complex_subscript:
+ return NO
+
+ return SPACE
if prevp.type == token.EQUAL:
if prevp.parent:
elif prevp.type == token.COLON:
if prevp.parent and prevp.parent.type in {syms.subscript, syms.sliceop}:
- return NO
+ return SPACE if complex_subscript else NO
elif (
prevp.parent
if prev and prev.type == token.LPAR:
return NO
- elif p.type == syms.subscript:
+ elif p.type in {syms.subscript, syms.sliceop}:
# indexing
if not prev:
assert p.parent is not None, "subscripts are always parented"
return NO
- else:
+ elif not complex_subscript:
return NO
elif p.type == syms.atom:
return None
+def child_towards(ancestor: Node, descendant: LN) -> Optional[LN]:
+ """Return the child of `ancestor` that contains `descendant`."""
+ node: Optional[LN] = descendant
+ while node and node.parent != ancestor:
+ node = node.parent
+ return node
+
+
def is_split_after_delimiter(leaf: Leaf, previous: Leaf = None) -> int:
"""Return the priority of the `leaf` delimiter, given a line break after it.
and leaf.parent
and leaf.parent.type not in {syms.factor, syms.star_expr}
):
- return MATH_PRIORITY
+ return MATH_PRIORITIES[leaf.type]
if leaf.type in COMPARATORS:
return COMPARATOR_PRIORITY
return
line_str = str(line).strip("\n")
- if (
- len(line_str) <= line_length
- and "\n" not in line_str # multiline strings
- and not line.contains_standalone_comments()
- ):
+ if is_line_short_enough(line, line_length=line_length, line_str=line_str):
yield line
return
split_funcs: List[SplitFunc]
if line.is_def:
split_funcs = [left_hand_split]
- elif line.inside_brackets:
- split_funcs = [delimiter_split, standalone_comment_split, right_hand_split]
+ elif line.is_import:
+ split_funcs = [explode_split]
else:
- split_funcs = [right_hand_split]
+
+ def rhs(line: Line, py36: bool = False) -> Iterator[Line]:
+ for omit in generate_trailers_to_omit(line, line_length):
+ lines = list(right_hand_split(line, py36, 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.
+ yield from right_hand_split(line, py36)
+
+ if line.inside_brackets:
+ split_funcs = [delimiter_split, standalone_comment_split, rhs]
+ else:
+ split_funcs = [rhs]
for split_func in split_funcs:
# We are accumulating lines in `result` because we might want to abort
# mission and return the original line in the end, or attempt a different
"""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.
+ 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)
def right_hand_split(
line: Line, py36: bool = False, omit: Collection[LeafID] = ()
) -> Iterator[Line]:
- """Split line into many lines, starting with the last matching bracket pair."""
+ """Split line into many lines, starting with the last matching bracket pair.
+
+ If the split was by optional parentheses, attempt splitting without them, too.
+ `omit` is a collection of closing bracket IDs that shouldn't be considered for
+ this split.
+ """
head = Line(depth=line.depth)
body = Line(depth=line.depth + 1, inside_brackets=True)
tail = Line(depth=line.depth)
bracket_split_succeeded_or_raise(head, body, tail)
assert opening_bracket and closing_bracket
if (
+ # the opening bracket is an optional paren
opening_bracket.type == token.LPAR
and not opening_bracket.value
+ # the closing bracket is an optional paren
and closing_bracket.type == token.RPAR
and not closing_bracket.value
+ # there are no delimiters or standalone comments in the body
+ and not body.bracket_tracker.delimiters
+ and not line.contains_standalone_comments(0)
+ # and it's not an import (optional parens are the only thing we can split
+ # on in this case; attempting a split without them is a waste of time)
+ and not line.is_import
):
- # These parens were optional. If there aren't any delimiters or standalone
- # comments in the body, they were unnecessary and another split without
- # them should be attempted.
- if not (
- body.bracket_tracker.delimiters or line.contains_standalone_comments(0)
- ):
- omit = {id(closing_bracket), *omit}
+ omit = {id(closing_bracket), *omit}
+ try:
yield from right_hand_split(line, py36=py36, omit=omit)
return
+ except CannotSplit:
+ pass
ensure_visible(opening_bracket)
ensure_visible(closing_bracket)
current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets)
current_line.append(leaf)
- for leaf in line.leaves:
+ for index, leaf in enumerate(line.leaves):
yield from append_to_line(leaf)
- for comment_after in line.comments_after(leaf):
+ for comment_after in line.comments_after(leaf, index):
yield from append_to_line(comment_after)
lowest_depth = min(lowest_depth, leaf.bracket_depth)
current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets)
current_line.append(leaf)
- for leaf in line.leaves:
+ for index, leaf in enumerate(line.leaves):
yield from append_to_line(leaf)
- for comment_after in line.comments_after(leaf):
+ for comment_after in line.comments_after(leaf, index):
yield from append_to_line(comment_after)
if current_line:
yield current_line
+def explode_split(
+ line: Line, py36: bool = False, omit: Collection[LeafID] = ()
+) -> Iterator[Line]:
+ """Split by rightmost bracket and immediately split contents by a delimiter."""
+ new_lines = list(right_hand_split(line, py36, omit))
+ if len(new_lines) != 3:
+ yield from new_lines
+ return
+
+ yield new_lines[0]
+
+ try:
+ yield from delimiter_split(new_lines[1], py36)
+
+ except CannotSplit:
+ yield new_lines[1]
+
+ yield new_lines[2]
+
+
def is_import(leaf: Leaf) -> bool:
"""Return True if the given leaf starts an import statement."""
p = leaf.parent
leaf.prefix = ""
+def normalize_string_prefix(leaf: Leaf, remove_u_prefix: bool = False) -> None:
+ """Make all string prefixes lowercase.
+
+ If remove_u_prefix is given, also removes any u prefix from the string.
+
+ Note: Mutates its argument.
+ """
+ match = re.match(r"^([furbFURB]*)(.*)$", leaf.value, re.DOTALL)
+ assert match is not None, f"failed to match string {leaf.value!r}"
+ orig_prefix = match.group(1)
+ new_prefix = orig_prefix.lower()
+ if remove_u_prefix:
+ new_prefix = new_prefix.replace("u", "")
+ leaf.value = f"{new_prefix}{match.group(2)}"
+
+
def normalize_string_quotes(leaf: Leaf) -> None:
"""Prefer double quotes but only if it doesn't cause more escaping.
unescaped_new_quote = re.compile(rf"(([^\\]|^)(\\\\)*){new_quote}")
escaped_new_quote = re.compile(rf"([^\\]|^)\\(\\\\)*{new_quote}")
escaped_orig_quote = re.compile(rf"([^\\]|^)\\(\\\\)*{orig_quote}")
- body = leaf.value[first_quote_pos + len(orig_quote):-len(orig_quote)]
+ body = leaf.value[first_quote_pos + len(orig_quote) : -len(orig_quote)]
if "r" in prefix.casefold():
if unescaped_new_quote.search(body):
# There's at least one unescaped new_quote in this raw string
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
+ should be put.
+
Standardizes on visible parentheses for single-element tuples, and keeps
existing visible parentheses for other tuples and generator expressions.
"""
for child in list(node.children):
if check_lpar:
if child.type == syms.atom:
- if not (
- is_empty_tuple(child)
- or is_one_tuple(child)
- or max_delimiter_priority_in_atom(child) >= COMMA_PRIORITY
- ):
- first = child.children[0]
- last = child.children[-1]
- if first.type == token.LPAR and last.type == token.RPAR:
- # make parentheses invisible
- first.value = "" # type: ignore
- last.value = "" # type: ignore
+ maybe_make_parens_invisible_in_atom(child)
elif is_one_tuple(child):
# wrap child in visible parentheses
lpar = Leaf(token.LPAR, "(")
check_lpar = isinstance(child, Leaf) and child.value in parens_after
+def maybe_make_parens_invisible_in_atom(node: LN) -> bool:
+ """If it's safe, make the parens in the atom `node` invisible, recusively."""
+ if (
+ node.type != syms.atom
+ or is_empty_tuple(node)
+ or is_one_tuple(node)
+ or is_yield(node)
+ 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:
+ # make parentheses invisible
+ first.value = "" # type: ignore
+ last.value = "" # type: ignore
+ if len(node.children) > 1:
+ maybe_make_parens_invisible_in_atom(node.children[1])
+ return True
+
+ return False
+
+
def is_empty_tuple(node: LN) -> bool:
"""Return True if `node` holds an empty tuple."""
return (
)
+def is_yield(node: LN) -> bool:
+ """Return True if `node` holds a `yield` or `yield from` expression."""
+ if node.type == syms.yield_expr:
+ return True
+
+ if node.type == token.NAME and node.value == "yield": # type: ignore
+ return True
+
+ if node.type != syms.atom:
+ return False
+
+ if len(node.children) != 3:
+ return False
+
+ lpar, expr, rpar = node.children
+ if lpar.type == token.LPAR and rpar.type == token.RPAR:
+ return is_yield(expr)
+
+ return False
+
+
def is_vararg(leaf: Leaf, within: Set[NodeType]) -> bool:
"""Return True if `leaf` is a star or double star in a vararg or kwarg.
If `within` includes VARARGS_PARENTS, this applies to function signatures.
- If `within` includes COLLECTION_LIBERALS_PARENTS, it applies to right
- hand-side extended iterable unpacking (PEP 3132) and additional unpacking
+ If `within` includes UNPACKING_PARENTS, it applies to right hand-side
+ extended iterable unpacking (PEP 3132) and additional unpacking
generalizations (PEP 448).
"""
if leaf.type not in STARS or not leaf.parent:
Currently looking for:
- f-strings; and
- - trailing commas after * or ** in function signatures.
+ - trailing commas after * or ** in function signatures and calls.
"""
for n in node.pre_order():
if n.type == token.STRING:
return True
elif (
- n.type == syms.typedargslist
+ n.type in {syms.typedargslist, syms.arglist}
and n.children
and n.children[-1].type == token.COMMA
):
if ch.type in STARS:
return True
+ if ch.type == syms.argument:
+ for argch in ch.children:
+ if argch.type in STARS:
+ return True
+
return False
+def generate_trailers_to_omit(line: Line, line_length: int) -> Iterator[Set[LeafID]]:
+ """Generate sets of closing bracket IDs that should be omitted in a RHS.
+
+ Brackets can be omitted if the entire trailer up to and including
+ a preceding closing bracket fits in one line.
+
+ Yielded sets are cumulative (contain results of previous yields, too). First
+ set is empty.
+ """
+
+ omit: Set[LeafID] = set()
+ yield omit
+
+ length = 4 * line.depth
+ opening_bracket = None
+ closing_bracket = None
+ optional_brackets: Set[LeafID] = set()
+ inner_brackets: Set[LeafID] = set()
+ for index, leaf in enumerate_reversed(line.leaves):
+ length += len(leaf.prefix) + len(leaf.value)
+ if length > line_length:
+ break
+
+ comment: Optional[Leaf]
+ for comment in line.comments_after(leaf, index):
+ if "\n" in comment.prefix:
+ break # Oops, standalone comment!
+
+ length += len(comment.value)
+ else:
+ comment = None
+ if comment is not None:
+ break # There was a standalone comment, we can't continue.
+
+ 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
+ # pair of brackets was good enough.
+ 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
+
+
+def get_future_imports(node: Node) -> Set[str]:
+ """Return a set of __future__ imports in the file."""
+ imports = set()
+ for child in node.children:
+ if child.type != syms.simple_stmt:
+ break
+ first_child = child.children[0]
+ if isinstance(first_child, Leaf):
+ # Continue looking if we see a docstring; otherwise stop.
+ if (
+ len(child.children) == 2
+ and first_child.type == token.STRING
+ and child.children[1].type == token.NEWLINE
+ ):
+ continue
+ else:
+ break
+ elif first_child.type == syms.import_from:
+ module_name = first_child.children[1]
+ if not isinstance(module_name, Leaf) or module_name.value != "__future__":
+ break
+ for import_from_child in first_child.children[3:]:
+ if isinstance(import_from_child, Leaf):
+ if import_from_child.type == token.NAME:
+ imports.add(import_from_child.value)
+ else:
+ assert import_from_child.type == syms.import_as_names
+ for leaf in import_from_child.children:
+ if isinstance(leaf, Leaf) and leaf.type == token.NAME:
+ imports.add(leaf.value)
+ else:
+ break
+ return imports
+
+
PYTHON_EXTENSIONS = {".py"}
BLACKLISTED_DIRECTORIES = {
"build", "buck-out", "dist", "_build", ".git", ".hg", ".mypy_cache", ".tox", ".venv"
yield from gen_python_files_in_dir(child)
- elif child.suffix in PYTHON_EXTENSIONS:
+ elif child.is_file() and child.suffix in PYTHON_EXTENSIONS:
yield child
return regex.sub(replacement, regex.sub(replacement, original))
+def enumerate_reversed(sequence: Sequence[T]) -> Iterator[Tuple[Index, T]]:
+ """Like `reversed(enumerate(sequence))` if that were possible."""
+ index = len(sequence) - 1
+ for element in reversed(sequence):
+ yield (index, element)
+ index -= 1
+
+
+def is_line_short_enough(line: Line, *, line_length: int, line_str: str = "") -> bool:
+ """Return True if `line` is no longer than `line_length`.
+
+ Uses the provided `line_str` rendering, if any, otherwise computes a new one.
+ """
+ if not line_str:
+ line_str = str(line).strip("\n")
+ return (
+ len(line_str) <= line_length
+ and "\n" not in line_str # multiline strings
+ and not line.contains_standalone_comments()
+ )
+
+
CACHE_DIR = Path(user_cache_dir("black", version=__version__))