On Thu, Dec 8, 2011 at 2:09 PM, Ethan Furman <et...@stoneleaf.us> wrote: > Benjamin Kaplan wrote: >> >> On Thu, Dec 8, 2011 at 1:42 PM, Roy Smith <r...@panix.com> wrote: >>> >>> (some, >>> very, >>> long, >>> list, >>> of, >>> variable, >>> names, >>> to, >>> get, >>> the, >>> stuff, >>> unpacked, >>> into) = function_that_should_return_a_14_tuple() >>> >>> raises >>> >>> ValueError: too many values to unpack >>> >>> Quick, what's the bug? Did I forget a variable on the LHS, or is my >>> function returning more things than it should? I know it's supposed to be >>> 14, but I don't know which side is wrong. Had it said "... expected 13, got >>> 14", I would know immediately. >>> >> >> If the RHS was a tuple or a list, yes you could know immediately. But >> unpacking works with any iterable, so it probably doesn't special-case >> lists and tuples. Iterables don't have a size- they just keep going >> until StopIteration is raised. So in EVERY SINGLE CASE, you would get >> "expected n args, got n+1" even if the iterable would return 24 items >> instead of 14, or would never stop returning items. > > > Not so. There could be fewer, in which you could see "expected 13 args, got > 7." >
You mean like this? >>> a,b,c = ['a','b'] Traceback (most recent call last): File "<stdin>", line 1, in <module> ValueError: need more than 2 values to unpack -- http://mail.python.org/mailman/listinfo/python-list
