[ python-Bugs-1110705 ] list comprehension scope

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Bugs item #1110705, was opened at 2005-01-27 15:27
Message generated for change (Comment added) made by sdahlbac
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Category: Python Interpreter Core
Group: Python 2.4
Status: Closed
Resolution: Invalid
Priority: 5
Submitted By: Simon Dahlbacka (sdahlbac)
Assigned to: Nobody/Anonymous (nobody)
Summary: list comprehension scope

Initial Comment:
The variable used for iteration in list comprehensions
is still in scope after the list comprehension. 

>>>foo = [1, 2, 3]
>>>bar = [dummy + 1 for dummy in foo]
>>>dummy
3

Expected result: NameError: name 'dummy' is not defined

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>Comment By: Simon Dahlbacka (sdahlbac)
Date: 2005-01-27 16:11

Message:
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Seemingly (according to:
http://docs.python.org/ref/lists.html) this is indeed a bug
that should be fixed.

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Comment By: Raymond Hettinger (rhettinger)
Date: 2005-01-27 15:48

Message:
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This is not a bug.  It is behaving as designed.  The thought
was to emulate the behavior of an equivalent for-loop.

In future versions of Python, Guido would like to change the
design to hide the induction variable.  So, someday, you'll
get your wish.

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