Bugs item #1466641, was opened at 2006-04-08 00:51
Message generated for change (Comment added) made by twouters
You can respond by visiting:
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1466641&group_id=5470
Please note that this message will contain a full copy of the comment thread,
including the initial issue submission, for this request,
not just the latest update.
Category: Parser/Compiler
Group: Python 2.5
>Status: Closed
>Resolution: Fixed
Priority: 7
Submitted By: Tim Peters (tim_one)
Assigned to: Thomas Wouters (twouters)
Summary: Bogus SyntaxError in listcomp
Initial Comment:
The attached syn.py gives a SyntaxError in 2.5a1 and
trunk. Works fine in earlier Pythons. Whittled down
from real-life Zope3 source.
def d(dir):
return [fn
for fn in os.listdir(dir)
if fn
if fn]
----------------------------------------------------------------------
>Comment By: Thomas Wouters (twouters)
Date: 2006-04-12 02:08
Message:
Logged In: YES
user_id=34209
Fixed in trunk, revision 45286.
----------------------------------------------------------------------
Comment By: Thomas Wouters (twouters)
Date: 2006-04-10 02:43
Message:
Logged In: YES
user_id=34209
Yeah, this is definately caused by the PEP 308 patch, so I
guess the error is mine (but don't tell anyone.) Unless
someone beats me to it, I'll fix it and add a test tomorrow
(but please don't fix it without checking in some tests.)
----------------------------------------------------------------------
Comment By: Georg Brandl (gbrandl)
Date: 2006-04-09 16:57
Message:
Logged In: YES
user_id=849994
Changing
list_if: 'if' test [list_iter]
to
list_if: 'if' old_test [list_iter]
solves the problem. Conditionals must then be enclosed in
parens.
Generator expressions are also affected.
----------------------------------------------------------------------
Comment By: Georg Brandl (gbrandl)
Date: 2006-04-09 16:50
Message:
Logged In: YES
user_id=849994
Haha. The second "if" is seen as the beginning of a
conditional expression, so
return [fn for fn in os.listdir(dir) if fn if fn else fn]
works.
----------------------------------------------------------------------
Comment By: Tim Peters (tim_one)
Date: 2006-04-09 06:07
Message:
Logged In: YES
user_id=31435
The whittled-down version looks ridiculous, but the original
wasn't quite such an affront to beauty :-) It's really no
stranger than allowing pure "if" statements to nest, and it
would be more painful to contort the grammar to disallow it
(I haven't looked at the 2.5 parser, but it was very
surprising to me that it didn't allow it!).
----------------------------------------------------------------------
Comment By: Nick Coghlan (ncoghlan)
Date: 2006-04-09 05:32
Message:
Logged In: YES
user_id=1038590
Is including two if clauses with a single for clause really
meant to be legal?
*goes and looks at language reference*
Wow. What a strange way to write "and". . .
----------------------------------------------------------------------
You can respond by visiting:
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1466641&group_id=5470
_______________________________________________
Python-bugs-list mailing list
Unsubscribe:
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
