[Python-checkins] python/dist/src/Doc/tut tut.tex,1.171,1.172

[rhettinger@users.sourceforge.net]

Update of /cvsroot/python/python/dist/src/Doc/tut
In directory usw-pr-cvs1:/tmp/cvs-serv20089

Modified Files:
	tut.tex 
Log Message:
Added a tutorial note and example regarding the scope of loop variables 
in a list comprehension.  Includes a justification and a comparision
to regular for-loops.

Closes SF bug 605047.



Index: tut.tex
===================================================================
RCS file: /cvsroot/python/python/dist/src/Doc/tut/tut.tex,v
retrieving revision 1.171
retrieving revision 1.172
diff -C2 -d -r1.171 -r1.172
*** tut.tex	21 Aug 2002 04:54:00 -0000	1.171
--- tut.tex	6 Sep 2002 18:06:04 -0000	1.172
***************
*** 1863,1866 ****
--- 1863,1879 ----
  \end{verbatim}
  
+ To make list comprehensions match the behavior of \keyword{for}
+ loops, assignments to the loop variable remain visible outside
+ of the comprehension:
+ 
+ \begin{verbatim}
+ >>> x = 100                     # this gets overwritten
+ >>> [x**3 for x in range(5)]
+ [0, 1, 8, 27, 64]
+ >>> x
+ 4                               # the final value for range(5)
+ >>
+ \end{verbatim}
+ 
  
  \section{The \keyword{del} statement \label{del}}