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author | Raymond Hettinger <python@rcn.com> | 2002-11-12 17:41:57 (GMT) |
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committer | Raymond Hettinger <python@rcn.com> | 2002-11-12 17:41:57 (GMT) |
commit | f24eb35d185c0623315cfbd9977d37c509860dcf (patch) | |
tree | 336a055089a3bd51d89bf4fdc987fb90ce743e09 /Doc | |
parent | 3a7ad5c5843467dc67ddf4c6622dd466f0f42c74 (diff) | |
download | cpython-f24eb35d185c0623315cfbd9977d37c509860dcf.zip cpython-f24eb35d185c0623315cfbd9977d37c509860dcf.tar.gz cpython-f24eb35d185c0623315cfbd9977d37c509860dcf.tar.bz2 |
SF patch 629637: Add sample(population, k) method to the random module.
Used for random sampling without replacement.
Diffstat (limited to 'Doc')
-rw-r--r-- | Doc/lib/librandom.tex | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/Doc/lib/librandom.tex b/Doc/lib/librandom.tex index 846b931..15e477b 100644 --- a/Doc/lib/librandom.tex +++ b/Doc/lib/librandom.tex @@ -179,6 +179,25 @@ Functions for sequences: long sequence can never be generated. \end{funcdesc} +\begin{funcdesc}{sample}{population, k} + Return a \var{k} length list of unique elements chosen from the + population sequence. Used for random sampling without replacement. + + Returns a new list containing elements from the population. The + list itself is in random order so that all sub-slices are also + random samples. The original sequence is left undisturbed. + + If the population has repeated elements, then each occurence is a + possible selection in the sample. + + If indices are needed for a large population, use \function{xrange} + as an argument: \code{sample(xrange(10000000), 60)}. + + Optional argument random is a 0-argument function returning a random + float in [0.0, 1.0); by default, the standard random.random. + \versionadded{2.3} +\end{funcdesc} + The following functions generate specific real-valued distributions. Function parameters are named after the corresponding variables in the |