python-patterns/patterns/behavioral/iterator.py at master · botdigit/python-patterns · GitHub

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#!/usr/bin/env python

# -*- coding: utf-8 -*-

"""

http://ginstrom.com/scribbles/2007/10/08/design-patterns-python-style/

Implementation of the iterator pattern with a generator

*TL;DR80

Traverses a container and accesses the container's elements.

"""

from __future__ import print_function

def count_to(count):

"""Counts by word numbers, up to a maximum of five"""

numbers = ["one", "two", "three", "four", "five"]

for number in numbers[:count]:

yield number

# Test the generator

count_to_two = lambda: count_to(2)

count_to_five = lambda: count_to(5)

def main():

"""

# Counting to two...

>>> for number in count_to_two():

... print(number)

one

two

# Counting to five...

>>> for number in count_to_five():

... print(number)

one

two

three

four

five

"""

if __name__ == "__main__":

import doctest

doctest.testmod()

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