Mapping Protocol
****************

int PyMapping_Check(PyObject *o)

   Return "1" if the object provides mapping protocol, and "0"
   otherwise.  This function always succeeds.

Py_ssize_t PyMapping_Size(PyObject *o)
Py_ssize_t PyMapping_Length(PyObject *o)

   Returns the number of keys in object *o* on success, and "-1" on
   failure.  For objects that do not provide mapping protocol, this is
   equivalent to the Python expression "len(o)".

int PyMapping_DelItemString(PyObject *o, const char *key)

   Remove the mapping for object *key* from the object *o*. Return
   "-1" on failure.  This is equivalent to the Python statement "del
   o[key]".

int PyMapping_DelItem(PyObject *o, PyObject *key)

   Remove the mapping for object *key* from the object *o*. Return
   "-1" on failure.  This is equivalent to the Python statement "del
   o[key]".

int PyMapping_HasKeyString(PyObject *o, const char *key)

   On success, return "1" if the mapping object has the key *key* and
   "0" otherwise.  This is equivalent to the Python expression "key in
   o". This function always succeeds.

int PyMapping_HasKey(PyObject *o, PyObject *key)

   Return "1" if the mapping object has the key *key* and "0"
   otherwise.  This is equivalent to the Python expression "key in o".
   This function always succeeds.

PyObject* PyMapping_Keys(PyObject *o)
    *Return value: New reference.*

   On success, return a list of the keys in object *o*.  On failure,
   return *NULL*. This is equivalent to the Python expression
   "list(o.keys())".

PyObject* PyMapping_Values(PyObject *o)
    *Return value: New reference.*

   On success, return a list of the values in object *o*.  On failure,
   return *NULL*. This is equivalent to the Python expression
   "list(o.values())".

PyObject* PyMapping_Items(PyObject *o)
    *Return value: New reference.*

   On success, return a list of the items in object *o*, where each
   item is a tuple containing a key-value pair.  On failure, return
   *NULL*. This is equivalent to the Python expression
   "list(o.items())".

PyObject* PyMapping_GetItemString(PyObject *o, const char *key)
    *Return value: New reference.*

   Return element of *o* corresponding to the object *key* or *NULL*
   on failure. This is the equivalent of the Python expression
   "o[key]".

int PyMapping_SetItemString(PyObject *o, const char *key, PyObject *v)

   Map the object *key* to the value *v* in object *o*. Returns "-1"
   on failure. This is the equivalent of the Python statement "o[key]
   = v".
