[Python-Dev] [PEP] += on return of function call result

[Jeff Epler]

It seems almost within the bounds of possibility that pychecker
could learn to find bugs of the form
    t = expression # t results from computation
    t += i         # inplace op on (immutable/no-__iadd__) t
    del t          # or t otherwise not used before function return
by doing type and liveness analysis on t. (the type analysis being the
hard part)

Is there any time that the described situation would not be a bug?  I
can't see it.

Jeff