| # 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 |
