assignment in control structure syntax (was Re: Curious assignment behaviour)

[Paul Rubin]

Chris Dutton <chris at cmb-enterprises.com> writes:
> > There are several other uses for this syntax.  For example,
> > 
> > if val = dict1[key1]; val:
> > process1(val)
> > elif val = dict2[key2]; val:
> > process2(val)
> > elif mylist += otherlist; len(mylist) > 4:
> > process3(mylist)

Hey, I like that, especially if you can use that PROG-like structure
in ordinary expressions, similar to the comma operator in C.

> The example I saw somewhere that I liked was
> 
> if something as x:
>    do_something_to(x)

That's ok too, as long as the comparison doesn't have to be with zero:
  if (something as x) == 3:
     do_something_to(x)