[Python-Dev] map, filter, zip in future_builtins

Tue Mar 18 21:54:05 CET 2008

I'm working on #2171 -- putting map, filter, zip in 2.6's 
future_builtins.
It has been suggested that it would be simplest to just return 
itertools.(imap, izip, ifilter), which is what py3k/Python/ 
bltinmodule.c, revision 61356 did.
The advantage of this is that it's really easy and the behaviour 
seems to be identical.
The disadvantage is that the two aren't identical:
 >>> type(map(lambda x: x, [1, 2, 3])) # Python 3
<type 'map'>
 >>> type(map(lambda x: x, [1, 2, 3])) == map
True
 >>> type(map(lambda x: x, [1, 2, 3])) # Python 2.6, with the patch
<type 'itertools.imap'>
 >>> type(map(lambda x: x, [1, 2, 3])) == map
False
Recommendations?