From 4109263a7edce11194e301138cf66fa2d07f7ce4 Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Thu, 22 Aug 2019 09:11:35 -0700 Subject: bpo-14050: Note that not all data can be sorted (GH-15381) --- Doc/tutorial/datastructures.rst | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/Doc/tutorial/datastructures.rst b/Doc/tutorial/datastructures.rst index 01e437b..a0d5627 100644 --- a/Doc/tutorial/datastructures.rst +++ b/Doc/tutorial/datastructures.rst @@ -125,6 +125,13 @@ only modify the list have no return value printed -- they return the default ``None``. [1]_ This is a design principle for all mutable data structures in Python. +Another thing you might notice is that not all data can be sorted or +compared. For instance, ``[None, 'hello', 10]`` doesn't sort because +integers can't be compared to strings and *None* can't be compared to +other types. Also, there are some types that don't have a defined +ordering relation. For example, ``3+4j < 5+7j`` isn't a valid +comparison. + .. _tut-lists-as-stacks: -- cgit v0.12