bpo-39374: Updated sorting documentation (GH-18177)

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Juhana Jauhiainen 2020-01-26 00:18:58 +02:00 committed by Raymond Hettinger
parent 4b09dc79f4
commit 8271441d8b
1 changed files with 6 additions and 4 deletions

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@ -43,16 +43,18 @@ Key Functions
=============
Both :meth:`list.sort` and :func:`sorted` have a *key* parameter to specify a
function to be called on each list element prior to making comparisons.
function (or other callable) to be called on each list element prior to making
comparisons.
For example, here's a case-insensitive string comparison:
>>> sorted("This is a test string from Andrew".split(), key=str.lower)
['a', 'Andrew', 'from', 'is', 'string', 'test', 'This']
The value of the *key* parameter should be a function that takes a single argument
and returns a key to use for sorting purposes. This technique is fast because
the key function is called exactly once for each input record.
The value of the *key* parameter should be a function (or other callable) that
takes a single argument and returns a key to use for sorting purposes. This
technique is fast because the key function is called exactly once for each
input record.
A common pattern is to sort complex objects using some of the object's indices
as keys. For example: