python -- @classmethod @staticmethod区别和使用

python中的定义：

class MyClass:
    ...
    @classmethod  # classmethod的修饰符
    def class_method(cls, arg1, arg2, ...):
        ...
    @staticmethod  # staticmethod的修饰符
    def static_method(arg1, arg2, ...):
        ...

@classmethod : 类方法

@staticmethod : 静态方法

类方法和静态方法的调用一样，都是通过类就可以直接调用。

区别：类方法，需要传入该类，定义类方法的时候要传一个默认的参数cls。静态方法则不用。

示例：

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#!/usr/bin/env python # -*- coding: utf-8 -*- # blog.ithomer.net   class Test(object):     x = 11     def __init__(self, _x):         self._x = _x         print("Test.__init__")        @classmethod     def class_method(cls):         print("class_method")        @staticmethod     def static_method():         print("static_method")        @classmethod     def getPt(cls):         cls.class_method()         cls.static_method()    if "__main__" == __name__:     Test.class_method()         # class_method     Test.static_method()        # static_method     Test.getPt()                # class_method  static_method       t = Test(22)                # Test.__init__     t.class_method()            # class_method     t.static_method()           # static_method           print Test.x                # 11 #     print Test._x           print t.x                   # 11     print t._x                  # 22       #     t.getPr()   # 'Test' object has no attribute 'getPr'

运行结果：

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class_method static_method class_method static_method Test.__init__ class_method static_method 11 11 22 Traceback (most recent call last):   File "/home/homer/workspace/myPython/com/connmiliao.py", line 40, in <module>     t.getPr() AttributeError: 'Test' object has no attribute 'getPr'</module>

示例：@property,@staticmethod,@classmethod 

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#!/usr/bin/env python # -*- coding: utf-8 -*- # blog.ithomer.net   class MyClass(object):     def __init__(self):         print '__init__'         self._name = 'blog.ithomer.net'       @staticmethod     def static_method():         print 'This is a static method!'       def test(self):         print 'call test'       @classmethod     def class_method(cls):         print 'cls: ',cls         print 'cls.name: ',cls.name         print 'cls.static_method(): ',cls.static_method()         instance = cls()         print 'instance.test(): ',instance.test()       @property     def name(self):         return self._name           @name.setter     def name(self, value):         self._name = value   if __name__ == '__main__':     MyClass.static_method()     MyClass.class_method()           mc = MyClass()     print mc.name     mc.name = 'forum.ithomer.net'      print mc.name

运行结果：

This is a static method!
cls: <class '__main__.myclass'="">
cls.name: 
cls.static_method(): This is a static method!
None
__init__
instance.test(): call test
None
__init__
blog.ithomer.net
forum.ithomer.net