Custom List/Iterator object, type in Python

http://www.rafekettler.com/magicmethods.html


http://stackoverflow.com/questions/19151/build-a-basic-python-iterator

class Counter:
    def __init__(self, low, high):
        self.current = low
        self.high = high

    def __iter__(self):
        return self

    def next(self):
        if self.current > self.high:
            raise StopIteration
        else:
            self.current += 1
            return self.current - 1

for c in Counter(3, 8):
    print c

This will print:

3
4
5
6
7
8

This is easier to write using a generator, as covered in a previous answer:

def counter(low, high):
    current = low
    while current <= high:
        yield current
        current += 1
for c in counter(3, 8):
    print c

2

http://stackoverflow.com/questions/4019971/how-to-implement-iter-self-for-a-container-object-python

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

This would create an iterator that returns five, and then every item in some_list.

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

3
python how to call __iter__ of base class? - Google Search


http://stackoverflow.com/questions/6560354/how-would-i-create-a-custom-list-class-in-python

Your can subclass list if your collection basically behaves like a list:

class MyCollection(list):
    def __init__(self, *args, **kwargs):
        super(MyCollection, self).__init__(args[0])

However, if your main wish is that your collection supports the iterator protocol, you just have to provide an __iter__ method:

class MyCollection(object):
    def __init__(self):
        self._data = [4, 8, 15, 16, 23, 42]

    def __iter__(self):
        for elem in self._data:
            yield elem

This allows you to iterate over any instance of MyCollection.

http://www.boduch.ca/2009/02/custom-python-iterators.html