Why '==' ??

[Tim Peters]

[John Roth]
> I believe the earliest versions of Python did use the single equal
> sign for comparisons. I don't know why Guido changed it, but
> it might be in order to keep his options open.

It was to stop ambiguity.  This was especially acute at an interactive
shell, where guessing what

>>> x = y

intended often guessed wrong <wink> (it's common to wonder whether two
things are equal at a shell prompt).  After the change, that became obvious:

>>> x = y  # assignment
>>> x == y # equal?
False
>>>