How to implement __iter__(self) for a container object (Python)

Question

I have written a custom container object.

According to this page, I need to implement this method on my object:

__iter__(self)

Howe

Answer 1

I normally would use a generator function. Each time you use a yield statement, it will add an item to the sequence.

The following will create an iterator that yields five, and then every item in some_list.

def __iter__(self):
   yield 5
   yield from some_list

Pre-3.3, yield from didn't exist, so you would have to do:

def __iter__(self):
   yield 5
   for x in some_list:
      yield x