Unpacking Argument Lists

［Unpacking Argument Lists］

　　The reverse situation occurs when the arguments are already in a list or tuple but need to be unpacked for a function call requiring separate positional arguments. For instance, the built-in range()function expects separate start and stop arguments. If they are not available separately, write the function call with the *-operator to unpack the arguments out of a list or tuple:

　　

　　In the same fashion, dictionaries can deliver keyword arguments with the **-operator:

　　

参考:http://docs.python.org/2.7/tutorial/controlflow.html#unpacking-argument-lists