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| author | Raymond Hettinger <python@rcn.com> | 2004-12-02 08:59:14 (GMT) |
|---|---|---|
| committer | Raymond Hettinger <python@rcn.com> | 2004-12-02 08:59:14 (GMT) |
| commit | 4901a1f267e9d632f85054ce8b21ff23bff305e1 (patch) | |
| tree | 27fdb176c85c194cc32d9a72d4812860bd2c4fb6 /Doc/lib/libheapq.tex | |
| parent | de7b99045d6ee40c2f6b0abbf9d1b5345d9cf15e (diff) | |
| download | cpython-4901a1f267e9d632f85054ce8b21ff23bff305e1.zip cpython-4901a1f267e9d632f85054ce8b21ff23bff305e1.tar.gz cpython-4901a1f267e9d632f85054ce8b21ff23bff305e1.tar.bz2 | |
Add key= argument to heapq.nsmallest() and heapq.nlargest().
Diffstat (limited to 'Doc/lib/libheapq.tex')
| -rw-r--r-- | Doc/lib/libheapq.tex | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/Doc/lib/libheapq.tex b/Doc/lib/libheapq.tex index 55ef641..eaf7051 100644 --- a/Doc/lib/libheapq.tex +++ b/Doc/lib/libheapq.tex @@ -90,16 +90,24 @@ True The module also offers two general purpose functions based on heaps. -\begin{funcdesc}{nlargest}{n, iterable} +\begin{funcdesc}{nlargest}{n, iterable\optional{, key}} Return a list with the \var{n} largest elements from the dataset defined -by \var{iterable}. Equivalent to: \code{sorted(iterable, reverse=True)[:n]} -\versionadded{2.4} +by \var{iterable}. \var{key}, if provided, specifies a function of one +argument that is used to extract a comparison key from each element +in the iterable: \samp{\var{key}=\function{str.lower}} +Equivalent to: \samp{sorted(iterable, key=key, reverse=True)[:n]} +\versionadded{2.4} +\versionchanged[Added the optional \var{key} argument]{2.5} \end{funcdesc} -\begin{funcdesc}{nsmallest}{n, iterable} +\begin{funcdesc}{nsmallest}{n, iterable\optional{, key}} Return a list with the \var{n} smallest elements from the dataset defined -by \var{iterable}. Equivalent to: \code{sorted(iterable)[:n]} -\versionadded{2.4} +by \var{iterable}. \var{key}, if provided, specifies a function of one +argument that is used to extract a comparison key from each element +in the iterable: \samp{\var{key}=\function{str.lower}} +Equivalent to: \samp{sorted(iterable, key=key)[:n]} +\versionadded{2.4} +\versionchanged[Added the optional \var{key} argument]{2.5} \end{funcdesc} Both functions perform best for smaller values of \var{n}. For larger |