Why = = (and not just =)

[Peter Otten]

Joe Green wrote:

> Sorry, I cant help aking stupid questions:
> 
> I understand why we need = = in C, but why in Python (or Java),
> surely if you write
>  if a=b: pass # syntax error
> it could not possibly mean anything other than what I intended
> (which was of course if a = = b:) ?

I don't particularly like it, but you can chain assignments:

>>> b = 1
>>> a = b = 2
>>> a,b
(2, 2)

>>> a = b == 2
>>> a,b
(True, 2)
>>>

HTH, 
Peter