Python range() builtin function, erm... malfunctioning with Django

Question

What, if anything, is wrong with this line of python code:

daterange = [begin + timedelta(n) for n in range((end - begin).days)]

Where begin and end are datetime.date objects with valid values.

I'm using this in a Django view to process some data, but everytime the view this is in gets called I get the following error with the aforementioned line highlighted:

UnboundLocalError at /url/of/error/creating/view/here/
local variable 'range' referenced before assignment

If I execute this line inside the interpreter it works fine, but somehow it doesn't fly inside a Django view. I don't understand why range is being interpreted as a variable name at all. Is there actually something wrong with this line, or is it something else in the code that's making Django complain?

Help!

Answer 1

There's nothing wrong with Django. You create a local variable range in the same scope (by assigning one). For instance range = None in the very last line of a function makes Python consider an occurrence of range in the first line of the same function a reference to that local variable. Since it doesn't have a value assigned at that point, you get an UnboundLocalError.