返回 1 if the object provides mapping protocol, and 0 otherwise. This function always succeeds.
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) .
Changed in version 2.5: These functions returned an int type. This might require changes in your code for properly supporting 64-bit systems.
Remove the mapping for object key from the object o 。返回 -1 on failure. This is equivalent to the Python statement del o[key] .
Remove the mapping for object key from the object o 。返回 -1 on failure. This is equivalent to the Python statement del o[key] .
On success, return 1 if the mapping object has the key key and 0 otherwise. This is equivalent to o[key] ,返回 True on success and False on an exception. This function always succeeds.
返回 1 if the mapping object has the key key and 0 otherwise. This is equivalent to o[key] ,返回 True on success and False on an exception. This function always succeeds.
On success, return a list of the keys in object o . On failure, return NULL . This is equivalent to the Python expression o.keys() .
On success, return a list of the values in object o . On failure, return NULL . This is equivalent to the Python expression o.values() .
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 o.items() .