diff options
| -rw-r--r-- | Doc/library/functions.rst | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst index 9629ace..e89323f 100644 --- a/Doc/library/functions.rst +++ b/Doc/library/functions.rst @@ -1603,6 +1603,15 @@ are always available. They are listed here in alphabetical order. compare equal --- this is helpful for sorting in multiple passes (for example, sort by department, then by salary grade). + The sort algorithm uses only ``<`` comparisons between items. While + defining an :meth:`~object.__lt__` method will suffice for sorting, + :PEP:`8` recommends that all six :ref:`rich comparisons + <comparisons>` be implemented. This will help avoid bugs when using + the same data with other ordering tools such as :func:`max` that rely + on a different underlying method. Implementing all six comparisons + also helps avoid confusion for mixed type comparisons which can call + reflected the :meth:`~object.__gt__` method. + For sorting examples and a brief sorting tutorial, see :ref:`sortinghowto`. .. decorator:: staticmethod |