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| author | Raymond Hettinger <python@rcn.com> | 2002-09-06 18:06:04 (GMT) |
|---|---|---|
| committer | Raymond Hettinger <python@rcn.com> | 2002-09-06 18:06:04 (GMT) |
| commit | 44c42b9cf33fac19ef0785ba3be9fc05f0be4dec (patch) | |
| tree | 4320f1499512c0ddfcabcd824d78ee9aedb9f03a /Doc/tut | |
| parent | 9ab7dd4d5b616cd9486d3a73a5e8320f8c913a1a (diff) | |
| download | cpython-44c42b9cf33fac19ef0785ba3be9fc05f0be4dec.zip cpython-44c42b9cf33fac19ef0785ba3be9fc05f0be4dec.tar.gz cpython-44c42b9cf33fac19ef0785ba3be9fc05f0be4dec.tar.bz2 | |
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.
Diffstat (limited to 'Doc/tut')
| -rw-r--r-- | Doc/tut/tut.tex | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/Doc/tut/tut.tex b/Doc/tut/tut.tex index 1990ab8..512dd6e 100644 --- a/Doc/tut/tut.tex +++ b/Doc/tut/tut.tex @@ -1862,6 +1862,19 @@ SyntaxError: invalid syntax [8, 12, -54] \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}} |