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# Copyright 2007 Google, Inc. All Rights Reserved.
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# Licensed to PSF under a Contributor Agreement.
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"""Fixer for dict methods.
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d.keys() -> list(d.keys())
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d.items() -> list(d.items())
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d.values() -> list(d.values())
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d.iterkeys() -> iter(d.keys())
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d.iteritems() -> iter(d.items())
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d.itervalues() -> iter(d.values())
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Except in certain very specific contexts: the iter() can be dropped
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when the context is list(), sorted(), iter() or for...in; the list()
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can be dropped when the context is list() or sorted() (but not iter()
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or for...in!). Special contexts that apply to both: list(), sorted(), tuple()
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set(), any(), all(), sum().
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Note: iter(d.keys()) could be written as iter(d) but since the
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original d.iterkeys() was also redundant we don't fix this. And there
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are (rare) contexts where it makes a difference (e.g. when passing it
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as an argument to a function that introspects the argument).
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from .. import patcomp
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from ..pgen2 import token
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from .. import fixer_base
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from ..fixer_util import Name, Call, LParen, RParen, ArgList, Dot
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from .. import fixer_util
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iter_exempt = fixer_util.consuming_calls | set(["iter"])
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class FixDict(fixer_base.BaseFix):
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trailer< '.' method=('keys'|'items'|'values'|
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'iterkeys'|'iteritems'|'itervalues') >
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parens=trailer< '(' ')' >
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def transform(self, node, results):
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head = results["head"]
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method = results["method"][0] # Extract node for method name
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tail = results["tail"]
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method_name = method.value
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isiter = method_name.startswith("iter")
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method_name = method_name[4:]
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assert method_name in ("keys", "items", "values"), repr(method)
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head = [n.clone() for n in head]
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tail = [n.clone() for n in tail]
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special = not tail and self.in_special_context(node, isiter)
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args = head + [pytree.Node(syms.trailer,
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prefix=method.get_prefix())]),
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results["parens"].clone()]
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new = pytree.Node(syms.power, args)
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new = Call(Name(isiter and "iter" or "list"), [new])
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new = pytree.Node(syms.power, [new] + tail)
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new.set_prefix(node.get_prefix())
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P1 = "power< func=NAME trailer< '(' node=any ')' > any* >"
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p1 = patcomp.compile_pattern(P1)
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P2 = """for_stmt< 'for' any 'in' node=any ':' any* >
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| comp_for< 'for' any 'in' node=any any* >
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p2 = patcomp.compile_pattern(P2)
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def in_special_context(self, node, isiter):
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if node.parent is None:
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if (node.parent.parent is not None and
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self.p1.match(node.parent.parent, results) and
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results["node"] is node):
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# iter(d.iterkeys()) -> iter(d.keys()), etc.
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return results["func"].value in iter_exempt
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# list(d.keys()) -> list(d.keys()), etc.
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return results["func"].value in fixer_util.consuming_calls
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# for ... in d.iterkeys() -> for ... in d.keys(), etc.
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return self.p2.match(node.parent, results) and results["node"] is node