Python/docs/3.8/c-api/mapping

Mapping Protocol

See also PyObject_GetItem(), PyObject_SetItem() and PyObject_DelItem().

int PyMapping_Check(PyObject *o)

Return 1 if the object provides mapping protocol or supports slicing, and 0 otherwise. Note that it returns 1 for Python classes with a __getitem__() method since in general case it is impossible to determine what type of keys it supports. 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. This is equivalent to the Python expression len(o).

PyObject* PyMapping_GetItemString(PyObject *o, const char *key)

Return value: New reference.

Return element of o corresponding to the string key or NULL on failure. This is the equivalent of the Python expression o[key]. See also PyObject_GetItem().

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

Map the string key to the value v in object o. Returns -1 on failure. This is the equivalent of the Python statement o[key] = v. See also PyObject_SetItem(). This function does not steal a reference to v.

int PyMapping_DelItem(PyObject *o, PyObject *key)

Remove the mapping for the object key from the object o. Return -1 on failure. This is equivalent to the Python statement del o[key]. This is an alias of PyObject_DelItem().

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

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

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.

Note that exceptions which occur while calling the __getitem__() method will get suppressed. To get error reporting use PyObject_GetItem() instead.

int PyMapping_HasKeyString(PyObject *o, const char *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.

Note that exceptions which occur while calling the __getitem__() method and creating a temporary string object will get suppressed. To get error reporting use PyMapping_GetItemString() instead.

PyObject* PyMapping_Keys(PyObject *o)

Return value: New reference.

On success, return a list of the keys in object o. On failure, return NULL.

Changed in version 3.7: Previously, the function returned a list or a tuple.

PyObject* PyMapping_Values(PyObject *o)

Return value: New reference.

On success, return a list of the values in object o. On failure, return NULL.

Changed in version 3.7: Previously, the function returned a list or a tuple.

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.

Changed in version 3.7: Previously, the function returned a list or a tuple.