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;
- trailing commas after * or ** in function signatures and calls;
- positional only arguments in function signatures and lambdas;
- assignment expression;
- relaxed decorator syntax;
"""
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"}:
features.add(Feature.F_STRINGS)
elif n.type == token.NUMBER:
if "_" in n.value: # type: ignore
features.add(Feature.NUMERIC_UNDERSCORES)
elif n.type == token.SLASH:
if n.parent and n.parent.type in {syms.typedargslist, syms.arglist}:
features.add(Feature.POS_ONLY_ARGUMENTS)
elif n.type == token.COLONEQUAL:
features.add(Feature.ASSIGNMENT_EXPRESSIONS)
elif n.type == syms.decorator:
if len(n.children) > 1 and not is_simple_decorator_expression(
n.children[1]
):
features.add(Feature.RELAXED_DECORATORS)
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:
features.add(feature)
if ch.type == syms.argument:
for argch in ch.children:
if argch.type in STARS:
features.add(feature)
return features
def get_features_used(node: Node) -> Set[Feature]: # noqa: C901
"""Return a set of (relatively) new Python features used in this file.
Currently looking for:
- f-strings;
- underscores in numeric literals;
- trailing commas after * or ** in function signatures and calls;
- positional only arguments in function signatures and lambdas;
- assignment expression;
- relaxed decorator syntax;
- print / exec statements;
"""
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"}:
features.add(Feature.F_STRINGS)
elif n.type == token.NUMBER:
assert isinstance(n, Leaf)
if "_" in n.value:
features.add(Feature.NUMERIC_UNDERSCORES)
elif n.value.endswith(("L", "l")):
# Python 2: 10L
features.add(Feature.LONG_INT_LITERAL)
elif len(n.value
) >= 2 and n.value[0] == "0" and n.value[1].isdigit():
# Python 2: 0123; 00123; ...
if not all(char == "0" for char in n.value):
# although we don't want to match 0000 or similar
features.add(Feature.OCTAL_INT_LITERAL)
elif n.type == token.SLASH:
if n.parent and n.parent.type in {
syms.typedargslist,
syms.arglist,
syms.varargslist,
}:
features.add(Feature.POS_ONLY_ARGUMENTS)
elif n.type == token.COLONEQUAL:
features.add(Feature.ASSIGNMENT_EXPRESSIONS)
elif n.type == syms.decorator:
if len(n.children) > 1 and not is_simple_decorator_expression(
n.children[1]):
features.add(Feature.RELAXED_DECORATORS)
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:
features.add(feature)
if ch.type == syms.argument:
for argch in ch.children:
if argch.type in STARS:
features.add(feature)
# Python 2 only features (for its deprecation) except for integers, see above
elif n.type == syms.print_stmt:
features.add(Feature.PRINT_STMT)
elif n.type == syms.exec_stmt:
features.add(Feature.EXEC_STMT)
elif n.type == syms.tfpdef:
# def set_position((x, y), value):
# ...
features.add(Feature.AUTOMATIC_PARAMETER_UNPACKING)
elif n.type == syms.except_clause:
# try:
# ...
# except Exception, err:
# ...
if len(n.children) >= 4:
if n.children[-2].type == token.COMMA:
features.add(Feature.COMMA_STYLE_EXCEPT)
elif n.type == syms.raise_stmt:
# raise Exception, "msg"
if len(n.children) >= 4:
if n.children[-2].type == token.COMMA:
features.add(Feature.COMMA_STYLE_RAISE)
elif n.type == token.BACKQUOTE:
# `i'm surprised this ever existed`
features.add(Feature.BACKQUOTE_REPR)
return features
def get_features_used( # noqa: C901
node: Node,
*,
future_imports: Optional[Set[str]] = None) -> Set[Feature]:
"""Return a set of (relatively) new Python features used in this file.
Currently looking for:
- f-strings;
- underscores in numeric literals;
- trailing commas after * or ** in function signatures and calls;
- positional only arguments in function signatures and lambdas;
- assignment expression;
- relaxed decorator syntax;
- usage of __future__ flags (annotations);
- print / exec statements;
"""
features: Set[Feature] = set()
if future_imports:
features |= {
FUTURE_FLAG_TO_FEATURE[future_import]
for future_import in future_imports
if future_import in FUTURE_FLAG_TO_FEATURE
}
for n in node.pre_order():
if is_string_token(n):
value_head = n.value[:2]
if value_head in {'f"', 'F"', "f'", "F'", "rf", "fr", "RF", "FR"}:
features.add(Feature.F_STRINGS)
elif n.type == token.NUMBER:
assert isinstance(n, Leaf)
if "_" in n.value:
features.add(Feature.NUMERIC_UNDERSCORES)
elif n.type == token.SLASH:
if n.parent and n.parent.type in {
syms.typedargslist,
syms.arglist,
syms.varargslist,
}:
features.add(Feature.POS_ONLY_ARGUMENTS)
elif n.type == token.COLONEQUAL:
features.add(Feature.ASSIGNMENT_EXPRESSIONS)
elif n.type == syms.decorator:
if len(n.children) > 1 and not is_simple_decorator_expression(
n.children[1]):
features.add(Feature.RELAXED_DECORATORS)
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:
features.add(feature)
if ch.type == syms.argument:
for argch in ch.children:
if argch.type in STARS:
features.add(feature)
elif (n.type in {syms.return_stmt, syms.yield_expr}
and len(n.children) >= 2
and n.children[1].type == syms.testlist_star_expr
and any(child.type == syms.star_expr
for child in n.children[1].children)):
features.add(Feature.UNPACKING_ON_FLOW)
elif (n.type == syms.annassign and len(n.children) >= 4
and n.children[3].type == syms.testlist_star_expr):
features.add(Feature.ANN_ASSIGN_EXTENDED_RHS)
elif (n.type == syms.except_clause and len(n.children) >= 2
and n.children[1].type == token.STAR):
features.add(Feature.EXCEPT_STAR)
return features
