📁 /snap/core20/current/lib/python3.8/lib2to3/fixes/fix_dict.py
# Copyright 2007 Google, Inc. All Rights Reserved.
# Licensed to PSF under a Contributor Agreement.
"""Fixer for dict methods.
d.keys() -> list(d.keys())
d.items() -> list(d.items())
d.values() -> list(d.values())
d.iterkeys() -> iter(d.keys())
d.iteritems() -> iter(d.items())
d.itervalues() -> iter(d.values())
d.viewkeys() -> d.keys()
d.viewitems() -> d.items()
d.viewvalues() -> d.values()
Except in certain very specific contexts: the iter() can be dropped
when the context is list(), sorted(), iter() or for...in; the list()
can be dropped when the context is list() or sorted() (but not iter()
or for...in!). Special contexts that apply to both: list(), sorted(), tuple()
set(), any(), all(), sum().
Note: iter(d.keys()) could be written as iter(d) but since the
original d.iterkeys() was also redundant we don't fix this. And there
are (rare) contexts where it makes a difference (e.g. when passing it
as an argument to a function that introspects the argument).
"""
# Local imports
from .. import pytree
from .. import patcomp
from .. import fixer_base
from ..fixer_util import Name, Call, Dot
from .. import fixer_util
iter_exempt = fixer_util.consuming_calls | {"iter"}
class FixDict(fixer_base.BaseFix):
BM_compatible = True
PATTERN = """
power< head=any+
trailer< '.' method=('keys'|'items'|'values'|
'iterkeys'|'iteritems'|'itervalues'|
'viewkeys'|'viewitems'|'viewvalues') >
parens=trailer< '(' ')' >
tail=any*
>
"""
def transform(self, node, results):
head = results["head"]
method = results["method"][0] # Extract node for method name
tail = results["tail"]
syms = self.syms
method_name = method.value
isiter = method_name.startswith("iter")
isview = method_name.startswith("view")
if isiter or isview:
method_name = method_name[4:]
assert method_name in ("keys", "items", "values"), repr(method)
head = [n.clone() for n in head]
tail = [n.clone() for n in tail]
special = not tail and self.in_special_context(node, isiter)
args = head + [pytree.Node(syms.trailer,
[Dot(),
Name(method_name,
prefix=method.prefix)]),
results["parens"].clone()]
new = pytree.Node(syms.power, args)
if not (special or isview):
new.prefix = ""
new = Call(Name("iter" if isiter else "list"), [new])
if tail:
new = pytree.Node(syms.power, [new] + tail)
new.prefix = node.prefix
return new
P1 = "power< func=NAME trailer< '(' node=any ')' > any* >"
p1 = patcomp.compile_pattern(P1)
P2 = """for_stmt< 'for' any 'in' node=any ':' any* >
| comp_for< 'for' any 'in' node=any any* >
"""
p2 = patcomp.compile_pattern(P2)
def in_special_context(self, node, isiter):
if node.parent is None:
return False
results = {}
if (node.parent.parent is not None and
self.p1.match(node.parent.parent, results) and
results["node"] is node):
if isiter:
# iter(d.iterkeys()) -> iter(d.keys()), etc.
return results["func"].value in iter_exempt
else:
# list(d.keys()) -> list(d.keys()), etc.
return results["func"].value in fixer_util.consuming_calls
if not isiter:
return False
# for ... in d.iterkeys() -> for ... in d.keys(), etc.
return self.p2.match(node.parent, results) and results["node"] is node