On 10/26/12 19:18, Steven D'Aprano wrote: > def iterate_until_none_or_false(func, *args, **kwargs): > while True: > x = func(*args, **kwargs) > # Halt if x is None or False, but not other falsey values. > if x is None or x is False: > return > yield x > > for x in iterate_until_none_or_false( > some_function, 1, 2, "c", spam="yummy"): > process(x)
I was initially a pretty strong advocate of the proposed "as" syntax. However, the more I've thought about it, the more I keep coming back to how I've solved the problem in the past which is mostly what Steven suggests here. There are so many edge-cases and warts in the "as" syntax; most of which disappear with this generator+forloop: - yielding/unpacking multiple results each time: the "as" syntax would get really ugly. Do you test the whole result, or an element of the result? - knowing the stopping condition varies: is it when something is False-ish (an empty string/tuple/list, False, None, etc)? When it "is None"? When it is exactly "False"? - the whole "x = (foo(bar) as result) if result else None" (or should that be "x = result if (foo(bar) as result) else None"?) style/discussion just really looks ugly to me. Usually I find Python code quite beautiful and this syntax doesn't resonate as "beautiful". To despite my previous excitement, I'm now neutral at best on a limited "while TERM as VAR:" syntax. I know this "being persuaded by rational arguments and changing one's mind" thing is rare on the Intarwebs, so I hope I haven't upset the natural balance of things too greatly. :-) -tkc -- http://mail.python.org/mailman/listinfo/python-list
