Python转载版

https://github.com/faif/python-patterns/blob/master/behavioral/template.py

#!/usr/bin/env python

-*- coding: utf-8 -*-

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

An example of the Template pattern in Python

*TL;DR80
Defines the skeleton of an algorithm, deferring steps to subclasses.
"""

ingredients = "spam eggs apple"
line = '-' * 10

Skeletons

def iter_elements(getter, action):
"""Template skeleton that iterates items"""
for element in getter():
action(element)
print(line)

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

Getters

def get_list():
return ingredients.split()

def get_lists():
return [list(x) for x in ingredients.split()]

Actions

def print_item(item):
print(item)

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

Makes templates

def make_template(skeleton, getter, action):
"""Instantiate a template method with getter and 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()

OUTPUT ###

spam

----------

eggs

----------

apple

----------

apple

----------

eggs

----------

spam

----------

maps

----------

sgge

----------

elppa

----------

elppa

----------

sgge

----------

maps

----------

['s', 'p', 'a', 'm']

----------

['e', 'g', 'g', 's']

----------

['a', 'p', 'p', 'l', 'e']

----------

['a', 'p', 'p', 'l', 'e']

----------

['e', 'g', 'g', 's']

----------

['s', 'p', 'a', 'm']

----------

['m', 'a', 'p', 's']

----------

['s', 'g', 'g', 'e']

----------

['e', 'l', 'p', 'p', 'a']

----------

['e', 'l', 'p', 'p', 'a']

----------

['s', 'g', 'g', 'e']

----------

['m', 'a', 'p', 's']

----------

Python转载版