Test None for an object that does not implement ==

[Paul Rudin]

I run into a weird problem. I have a piece of code that looks like the
following:

f(...., a=None, c=None):
assert (a==None)==(c==None)

There is only one 'None' - so use 'a is None' rather than 'a == None'.

(In common lisp there is a particular language construct that allows you
do determine whether an argument was passed in or was defaulted.)

 

[Ethan Furman]

He wants both or neither to be passed in.

Ah -- right.

~Ethan~