cpython/Lib/lib2to3/fixes/fix_map.py
Benjamin Peterson d9af52ba7e Merged revisions 76062 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk

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  r76062 | benjamin.peterson | 2009-11-02 12:12:12 -0600 (Mon, 02 Nov 2009) | 70 lines

  Merged revisions 74359,75081,75088,75213,75278,75303,75427-75428,75734-75736,75865,76059-76061 via svnmerge from
  svn+ssh://pythondev@svn.python.org/sandbox/trunk/2to3/lib2to3

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    r74359 | benjamin.peterson | 2009-08-12 17:23:13 -0500 (Wed, 12 Aug 2009) | 1 line

    don't pass the deprecated print_function option
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    r75081 | benjamin.peterson | 2009-09-26 22:02:57 -0500 (Sat, 26 Sep 2009) | 1 line

    let 2to3 work with extended iterable unpacking
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    r75088 | benjamin.peterson | 2009-09-27 11:25:21 -0500 (Sun, 27 Sep 2009) | 1 line

    look on the type only for __call__
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    r75213 | benjamin.peterson | 2009-10-03 10:09:46 -0500 (Sat, 03 Oct 2009) | 5 lines

    revert 75212; it's not correct

    People can use isinstance(x, collections.Callable) if they expect objects with
    __call__ in their instance dictionaries.
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    r75278 | benjamin.peterson | 2009-10-07 16:25:56 -0500 (Wed, 07 Oct 2009) | 4 lines

    fix whitespace problems with fix_idioms #3563

    Patch by Joe Amenta.
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    r75303 | benjamin.peterson | 2009-10-09 16:59:11 -0500 (Fri, 09 Oct 2009) | 1 line

    port latin-1 and utf-8 cookie improvements
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    r75427 | benjamin.peterson | 2009-10-14 20:35:57 -0500 (Wed, 14 Oct 2009) | 1 line

    force floor division
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    r75428 | benjamin.peterson | 2009-10-14 20:39:21 -0500 (Wed, 14 Oct 2009) | 1 line

    silence -3 warnings about __hash__
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    r75734 | benjamin.peterson | 2009-10-26 16:25:53 -0500 (Mon, 26 Oct 2009) | 2 lines

    warn on map(None, ...) with more than 2 arguments #7203
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    r75735 | benjamin.peterson | 2009-10-26 16:28:25 -0500 (Mon, 26 Oct 2009) | 1 line

    remove unused result
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    r75736 | benjamin.peterson | 2009-10-26 16:29:02 -0500 (Mon, 26 Oct 2009) | 1 line

    using get() here is a bit pointless
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    r75865 | benjamin.peterson | 2009-10-27 15:49:00 -0500 (Tue, 27 Oct 2009) | 1 line

    explain reason for warning
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    r76059 | benjamin.peterson | 2009-11-02 11:43:47 -0600 (Mon, 02 Nov 2009) | 1 line

    tuples are no longer used for children
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    r76060 | benjamin.peterson | 2009-11-02 11:55:40 -0600 (Mon, 02 Nov 2009) | 1 line

    revert r76059; apparently some fixers rely on Leaf no () for children
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    r76061 | benjamin.peterson | 2009-11-02 12:06:17 -0600 (Mon, 02 Nov 2009) | 1 line

    make fix_tuple_params keep the tree valid #7253
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2009-11-02 18:16:28 +00:00

90 lines
3 KiB
Python

# 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, Call, ListComp, in_special_context
from ..pygram import python_symbols as syms
class FixMap(fixer_base.ConditionalFix):
PATTERN = """
map_none=power<
'map'
trailer< '(' arglist< 'None' ',' arg=any [','] > ')' >
>
|
map_lambda=power<
'map'
trailer<
'('
arglist<
lambdef< 'lambda'
(fp=NAME | vfpdef< '(' fp=NAME ')'> ) ':' xp=any
>
','
it=any
>
')'
>
>
|
power<
'map' trailer< '(' [arglist=any] ')' >
>
"""
skip_on = 'future_builtins.map'
def transform(self, node, results):
if self.should_skip(node):
return
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())
else:
if "map_none" in results:
new = results["arg"].clone()
else:
if "arglist" in results:
args = results["arglist"]
if args.type == syms.arglist and \
args.children[0].type == token.NAME and \
args.children[0].value == "None":
self.warning(node, "cannot convert map(None, ...) "
"with multiple arguments because map() "
"now truncates to the shortest sequence")
return
if in_special_context(node):
return None
new = node.clone()
new.prefix = ""
new = Call(Name("list"), [new])
new.prefix = node.prefix
return new