diff options
Diffstat (limited to 'Doc')
| -rw-r--r-- | Doc/c-api/object.rst | 7 | ||||
| -rw-r--r-- | Doc/library/operator.rst | 6 |
2 files changed, 13 insertions, 0 deletions
diff --git a/Doc/c-api/object.rst b/Doc/c-api/object.rst index d895547..8458fe8 100644 --- a/Doc/c-api/object.rst +++ b/Doc/c-api/object.rst @@ -342,6 +342,13 @@ is considered sufficient for this determination. returned. This is the equivalent to the Python expression ``len(o)``. +.. c:function:: Py_ssize_t PyObject_LengthHint(PyObject *o, Py_ssize_t default) + + Return an estimated length for the object *o*. First trying to return its + actual length, then an estimate using ``__length_hint__``, and finally + returning the default value. On error ``-1`` is returned. This is the + equivalent to the Python expression ``operator.length_hint(o, default)``. + .. c:function:: PyObject* PyObject_GetItem(PyObject *o, PyObject *key) Return element of *o* corresponding to the object *key* or *NULL* on failure. diff --git a/Doc/library/operator.rst b/Doc/library/operator.rst index 3860880..93f33ff 100644 --- a/Doc/library/operator.rst +++ b/Doc/library/operator.rst @@ -235,6 +235,12 @@ their character equivalents. .. XXX: find a better, readable, example +.. function:: length_hint(obj, default=0) + + Return an estimated length for the object *o*. First trying to return its + actual length, then an estimate using ``__length_hint__``, and finally + returning the default value. + The :mod:`operator` module also defines tools for generalized attribute and item lookups. These are useful for making fast field extractors as arguments for :func:`map`, :func:`sorted`, :meth:`itertools.groupby`, or other functions that |