diff options
Diffstat (limited to 'Doc/reference')
| -rw-r--r-- | Doc/reference/datamodel.rst | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst index 8813f57587..6b9325da2f 100644 --- a/Doc/reference/datamodel.rst +++ b/Doc/reference/datamodel.rst @@ -2155,8 +2155,10 @@ through the container; for mappings, :meth:`__iter__` should be the same as Called to implement :func:`operator.length_hint`. Should return an estimated length for the object (which may be greater or less than the actual length). - The length must be an integer ``>=`` 0. This method is purely an - optimization and is never required for correctness. + The length must be an integer ``>=`` 0. The return value may also be + *NotImplemented*, which is treated the same as if the ``__length_hint__`` + method didn't exist at all. This method is purely an optimization and is + never required for correctness. .. versionadded:: 3.4 |