관리-도구

편집 파일: fix_map.py

# Copyright 2007 Google, Inc. All Rights Reserved. # Licensed to PSF under a Contributor Agreement. """Fixer that changes map(F, ...) into list(map(F, ...)) unless there exists a 'from future_builtins import map' statement in the top-level namespace. As a special case, map(None, X) is changed into list(X). (This is necessary because the semantics are changed in this case -- the new map(None, X) is equivalent to [(x,) for x in X].) We avoid the transformation (except for the special case mentioned above) if the map() 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 map(F, X, Y, ...) to go on until the longest argument is exhausted, substituting None for missing values -- like zip(), it now stops as soon as the shortest argument is exhausted. """ # Local imports from ..pgen2 import token from .. import fixer_base from ..fixer_util import Name, ArgList, Call, ListComp, in_special_context from ..pygram import python_symbols as syms from ..pytree import Node class FixMap(fixer_base.ConditionalFix): BM_compatible = True PATTERN = """ map_none=power< 'map' trailer< '(' arglist< 'None' ',' arg=any [','] > ')' > [extra_trailers=trailer*] > | map_lambda=power< 'map' trailer< '(' arglist< lambdef< 'lambda' (fp=NAME | vfpdef< '(' fp=NAME ')'> ) ':' xp=any > ',' it=any > ')' > [extra_trailers=trailer*] > | power< 'map' args=trailer< '(' [any] ')' > [extra_trailers=trailer*] > """ skip_on = 'future_builtins.map' 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 node.parent.type == syms.simple_stmt: self.warning(node, "You should use a for loop here") new = node.clone() new.prefix = "" new = Call(Name("list"), [new]) elif "map_lambda" in results: new = ListComp(results["xp"].clone(), results["fp"].clone(), results["it"].clone()) new = Node(syms.power, [new] + trailers, prefix="") else: if "map_none" in results: new = results["arg"].clone() new.prefix = "" else: if "args" in results: args = results["args"] if args.type == syms.trailer and \ args.children[1].type == syms.arglist and \ args.children[1].children[0].type == token.NAME and \ args.children[1].children[0].value == "None": self.warning(node, "cannot convert map(None, ...) " "with multiple arguments because map() " "now truncates to the shortest sequence") return new = Node(syms.power, [Name("map"), args.clone()]) new.prefix = "" if in_special_context(node): return None new = Node(syms.power, [Name("list"), ArgList([new])] + trailers) new.prefix = "" new.prefix = node.prefix return new