test.py

#coding: utf-8

'''An example of the Template pattern in Python

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

# Skeletons
def iter_elements(getter, action):
	'''Template skeleton that iterates items'''
	for element in getter():
		action(element)
	print '-' * 10

def rev_elements(getter, action):
	'''Template skeleton that iterates items in reverse order'''
	for element in getter()[::-1]:
		action(element)
	print '-' * 10

# Getters
def get_list():
	return "spam eggs".split()

def get_lists():
	return [list(x) for x in "spam eggs".split()]

# Actions
def print_item(item):
	print item

def reverse_item(item):
	print item[::-1]

# Makes templates
def make_template(skeleton, getter, action):
	'''Instance a template method with a getter and an action'''
	def template():
		skeleton(getter, action)
	return template

# Create our template functions
templates = [make_template(s, g, a)
		for g in (get_list, get_lists)
		for a in (print_item, reverse_item)
		for s in (iter_elements, rev_elements)]

# Execute them
for template in templates:
	template()