Why can't I iterate over a ListProperty in AppEngine?

Question

I've just got this error from Google App Engine:

TypeError: argument of type 'ListProperty' is not iterable

why?

Answer 1

Without seeing your code, it's impossible to see what exactly you're doing wrong, but it looks like you're trying to iterate over the property itself - eg, SomeClass.my_list - rather than an instance - eg, an_instance.my_list.