pythonic way to rewrite an assignment in an if statement

Question

Is there a pythonic preferred way to do this that I would do in C++:

for s in str:
    if r = regex.match(s):
        print r.groups()

I r

Answer 1

There's a recipe to make an assignment expression but it's very hacky. Your first option doesn't compile so your second option is the way to go.

## {{{ http://code.activestate.com/recipes/202234/ (r2)
import sys
def set(**kw):
    assert len(kw)==1

    a = sys._getframe(1)
    a.f_locals.update(kw)
    return kw.values()[0]

#
# sample
#

A=range(10)

while set(x=A.pop()):
    print x
## end of http://code.activestate.com/recipes/202234/ }}}

As you can see, production code shouldn't touch this hack with a ten foot, double bagged stick.