How do I use __getitem__ and __iter__ and return values from a dictionary?

Question

I have an object with a dictionary that I want to access via __getitem__ as well as iterate over (values only, keys don\'t matter) but am not sure how to do it.

Answer 1

Add this method to Library:

def __iter__(self):
  return self.books.itervalues()

This delegates iteration to the dict, which has an easy method to iterate values. Read about the iterator protocol, which consists of __iter__ (on all iterables) and next(__next__ in 3.x) (only on iterators) methods.