# Copyright 2007 Google, Inc. All Rights Reserved. # Licensed to PSF under a Contributor Agreement. """Fixer that changes filter(F, X) into list(filter(F, X)). We avoid the transformation if the filter() call is directly contained in iter(<>), list(<>), tuple(<>), sorted(<>), ...join(<>), or for V in <>:. NOTE: This is still not correct if the original code was depending on filter(F, X) to return a string if X is a string and a tuple if X is a tuple. That would require type inference, which we don't do. Let Python 2.6 figure it out. """ # Local imports from .. import fixer_base from ..pytree import Node from ..pygram import python_symbols as syms from ..fixer_util import Name, ArgList, ListComp, in_special_context, parenthesize class FixFilter(fixer_base.ConditionalFix): BM_compatible = True PATTERN = """ filter_lambda=power< 'filter' trailer< '(' arglist< lambdef< 'lambda' (fp=NAME | vfpdef< '(' fp=NAME ')'> ) ':' xp=any > ',' it=any > ')' > [extra_trailers=trailer*] > | power< 'filter' trailer< '(' arglist< none='None' ',' seq=any > ')' > [extra_trailers=trailer*] > | power< 'filter' args=trailer< '(' [any] ')' > [extra_trailers=trailer*] > """ skip_on = "future_builtins.filter" def transform(self, node, results): if self.should_skip(node): return trailers = [] if 'extra_trailers' in results: for t in results['extra_trailers']: trailers.append(t.clone()) if "filter_lambda" in results: xp = results.get("xp").clone() if xp.type == syms.test: xp.prefix = "" xp = parenthesize(xp) new = ListComp(results.get("fp").clone(), results.get("fp").clone(), results.get("it").clone(), xp) new = Node(syms.power, [new] + trailers, prefix="") elif "none" in results: new = ListComp(Name("_f"), Name("_f"), results["seq"].clone(), Name("_f")) new = Node(syms.power, [new] + trailers, prefix="") else: if in_special_context(node): return None args = results['args'].clone() new = Node(syms.power, [Name("filter"), args], prefix="") new = Node(syms.power, [Name("list"), ArgList([new])] + trailers) new.prefix = "" new.prefix = node.prefix return new