[Python] python: when can I unpack a generator? [duplicate]

How does it work under the hood? I don't understand the reason for the errors below:

>>> def f():
... yield 1,2
... yield 3,4
...
>>> *f()
File "<stdin>", line 1
*f()
^
SyntaxError: invalid syntax
>>> zip(*f())
[(1, 3), (2, 4)]
>>> zip(f())
[((1, 2),), ((3, 4),)]
>>> *args = *f()
File "<stdin>", line 1
*args = *f()
^
SyntaxError: invalid syntax

Continue reading...