functools.partial doesn't work without using named parameter

[Paddy]

Thanks Ian, Benjamin, and Steven.

I now know why it works as it does.

Thinking about it a little more, Is it reasonable to *expect* partial acts as it does, rather than this way being an implementation convenience? (That was written as a straight question not in any way as a dig).

I had thought that partial had enough information to, and would in fact, remove named parameter f from the signature of fsf1 returning something that could be called that is the equivalent of:

def fsf1_( s ): ...

I accept that that is not done, but would welcome discussion on if my expectation above was reasonable. 

Thanks guys :-)