What value should be passed to make a function use the default argument value?

[Stan Graves]

LaundroMat wrote:
> Suppose I have this function:
>
> def f(var=1):
> return var*2
>
> What value do I have to pass to f() if I want it to evaluate var to 1?
> I know that f() will return 2, but what if I absolutely want to pass a
> value to f()? "None" doesn't seem to work..


What about this?

>>> def f(var=None):
...     if var == None:
...         var = 1
...     return 2*var
...
>>> f()
2
>>> f(3)
6
>>> a=4
>>> f(a)
8
>>> b=None
>>> f(b)
2
>>> 

--Stan Graves