def remove_await_parens(node: Node) -> None:
if node.children[0].type == token.AWAIT and len(node.children) > 1:
if (
node.children[1].type == syms.atom
and node.children[1].children[0].type == token.LPAR
):
if maybe_make_parens_invisible_in_atom(
node.children[1],
parent=node,
remove_brackets_around_comma=True,
):
wrap_in_parentheses(node, node.children[1], visible=False)
# Since await is an expression we shouldn't remove
# brackets in cases where this would change
# the AST due to operator precedence.
# Therefore we only aim to remove brackets around
# power nodes that aren't also await expressions themselves.
# https://peps.python.org/pep-0492/#updated-operator-precedence-table
# N.B. We've still removed any redundant nested brackets though :)
opening_bracket = cast(Leaf, node.children[1].children[0])
closing_bracket = cast(Leaf, node.children[1].children[-1])
bracket_contents = cast(Node, node.children[1].children[1])
if bracket_contents.type != syms.power:
ensure_visible(opening_bracket)
ensure_visible(closing_bracket)
elif (
bracket_contents.type == syms.power
and bracket_contents.children[0].type == token.AWAIT
):
ensure_visible(opening_bracket)
ensure_visible(closing_bracket)
# If we are in a nested await then recurse down.
remove_await_parens(bracket_contents)
def left_hand_split(line: Line, _features: Collection[Feature] = ()) -> Iterator[Line]:
"""Split line into many lines, starting with the first matching bracket pair.
Note: this usually looks weird, only use this for function definitions.
Prefer RHS otherwise. This is why this function is not symmetrical with
:func:`right_hand_split` which also handles optional parentheses.
"""
tail_leaves: List[Leaf] = []
body_leaves: List[Leaf] = []
head_leaves: List[Leaf] = []
current_leaves = head_leaves
matching_bracket: Optional[Leaf] = None
for leaf in line.leaves:
if (
current_leaves is body_leaves
and leaf.type in CLOSING_BRACKETS
and leaf.opening_bracket is matching_bracket
and isinstance(matching_bracket, Leaf)
):
ensure_visible(leaf)
ensure_visible(matching_bracket)
current_leaves = tail_leaves if body_leaves else head_leaves
current_leaves.append(leaf)
if current_leaves is head_leaves:
if leaf.type in OPENING_BRACKETS:
matching_bracket = leaf
current_leaves = body_leaves
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:
yield result
def right_hand_split(
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.
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.
Note: running this function modifies `bracket_depth` on the leaves of `line`.
"""
tail_leaves: List[Leaf] = []
body_leaves: List[Leaf] = []
head_leaves: List[Leaf] = []
current_leaves = tail_leaves
opening_bracket: Optional[Leaf] = None
closing_bracket: Optional[Leaf] = None
for leaf in reversed(line.leaves):
if current_leaves is body_leaves:
if leaf is opening_bracket:
current_leaves = head_leaves if body_leaves else tail_leaves
current_leaves.append(leaf)
if current_leaves is tail_leaves:
if leaf.type in CLOSING_BRACKETS and id(leaf) not in omit:
opening_bracket = leaf.opening_bracket
closing_bracket = leaf
current_leaves = body_leaves
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")
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 (
Feature.FORCE_OPTIONAL_PARENTHESES not in features
# the opening bracket is an optional paren
and opening_bracket.type == token.LPAR
and not opening_bracket.value
# the closing bracket is an optional paren
and closing_bracket.type == token.RPAR
and not closing_bracket.value
# it's not an import (optional parens are the only thing we can split on
# in this case; attempting a split without them is a waste of time)
and not line.is_import
# there are no standalone comments in the body
and not body.contains_standalone_comments(0)
# and we can actually remove the parens
and can_omit_invisible_parens(body, line_length)
):
omit = {id(closing_bracket), *omit}
try:
yield from right_hand_split(line, line_length, features=features, omit=omit)
return
except CannotSplit as e:
if not (
can_be_split(body)
or is_line_short_enough(body, line_length=line_length)
):
raise CannotSplit(
"Splitting failed, body is still too long and can't be split."
) from e
elif head.contains_multiline_strings() or tail.contains_multiline_strings():
raise CannotSplit(
"The current optional pair of parentheses is bound to fail to"
" satisfy the splitting algorithm because the head or the tail"
" contains multiline strings which by definition never fit one"
" line."
) from e
ensure_visible(opening_bracket)
ensure_visible(closing_bracket)
for result in (head, body, tail):
if result:
yield result
