1.. highlightlang:: c
2
3.. _mapping:
4
5Mapping Protocol
6================
7
8
9.. c:function:: int PyMapping_Check(PyObject *o)
10
11   Return ``1`` if the object provides mapping protocol, and ``0`` otherwise.  This
12   function always succeeds.
13
14
15.. c:function:: Py_ssize_t PyMapping_Size(PyObject *o)
16               Py_ssize_t PyMapping_Length(PyObject *o)
17
18   .. index:: builtin: len
19
20   Returns the number of keys in object *o* on success, and ``-1`` on failure.  For
21   objects that do not provide mapping protocol, this is equivalent to the Python
22   expression ``len(o)``.
23
24
25.. c:function:: int PyMapping_DelItemString(PyObject *o, const char *key)
26
27   Remove the mapping for object *key* from the object *o*. Return ``-1`` on
28   failure.  This is equivalent to the Python statement ``del o[key]``.
29
30
31.. c:function:: int PyMapping_DelItem(PyObject *o, PyObject *key)
32
33   Remove the mapping for object *key* from the object *o*. Return ``-1`` on
34   failure.  This is equivalent to the Python statement ``del o[key]``.
35
36
37.. c:function:: int PyMapping_HasKeyString(PyObject *o, const char *key)
38
39   On success, return ``1`` if the mapping object has the key *key* and ``0``
40   otherwise.  This is equivalent to the Python expression ``key in o``.
41   This function always succeeds.
42
43
44.. c:function:: int PyMapping_HasKey(PyObject *o, PyObject *key)
45
46   Return ``1`` if the mapping object has the key *key* and ``0`` otherwise.  This
47   is equivalent to the Python expression ``key in o``.  This function always
48   succeeds.
49
50
51.. c:function:: PyObject* PyMapping_Keys(PyObject *o)
52
53   On success, return a list or tuple of the keys in object *o*.  On failure,
54   return *NULL*.
55
56
57.. c:function:: PyObject* PyMapping_Values(PyObject *o)
58
59   On success, return a list or tuple of the values in object *o*.  On failure,
60   return *NULL*.
61
62
63.. c:function:: PyObject* PyMapping_Items(PyObject *o)
64
65   On success, return a list or tuple of the items in object *o*, where each item
66   is a tuple containing a key-value pair.  On failure, return *NULL*.
67
68
69.. c:function:: PyObject* PyMapping_GetItemString(PyObject *o, const char *key)
70
71   Return element of *o* corresponding to the object *key* or *NULL* on failure.
72   This is the equivalent of the Python expression ``o[key]``.
73
74
75.. c:function:: int PyMapping_SetItemString(PyObject *o, const char *key, PyObject *v)
76
77   Map the object *key* to the value *v* in object *o*. Returns ``-1`` on failure.
78   This is the equivalent of the Python statement ``o[key] = v``.
79