優雅實現策略模式; 在awesome-python上有一個關于模式設計的包，對包中的代碼做了一點修改。

# -*- coding: utf-8 -*-"""http://stackoverflow.com/questions/963965/how-is-this-strategy-pattern -written-in-python-the-sample-in-wikipediaIn most of other languages Strategy pattern is implemented via creating somebase strategy interface/abstract class and subclassing it with a number ofconcrete strategies (as we can see athttp://en.wikipedia.org/wiki/Strategy_pattern), however Python supportshigher-order functions and allows us to have only one class and injectfunctions into it's instances, as shown in this example."""import typesclass StrategyExample:    def __init__(self, func=None):        self.name = 'Strategy Example 0'        if func is not None:            self.select(func)    def __call__(self, arg=''):   # special method for execute        self.execute()    def execute(self):        
輸出為
nothingnothingStrategy Example 1 from execute 1Strategy Example 2 from execute 2Strategy Example 2 from execute 1Strategy Example x from execute 2