Python实例方法与静态方法

Question

我试着学习python2.7。当我运行此代码时：

class MyClass:
    def PrintList1(*args):
        for Count, Item in enumerate(args):
            print("{0}. {1}".format(Count, Item))

    def PrintList2(**kwargs):
        for Name, Value in kwargs.items():
            print("{0} likes {1}".format(Name, Value))

MyClass.PrintList1("Red", "Blue", "Green")
MyClass.PrintList2(George="Red", Sue="Blue",Zarah="Green") 

我得到一个TypeError：

MyClass.PrintList1("Red", "Blue", "Green")
TypeError: unbound method PrintList1() must be called with MyClass instance    as first argument (got str instance instead)
>>> 

为什么

Answer 1

我的班级是，一个班级

PrintList1是一个方法

方法需要在类的实例对象上调用

像这样：

myObject = MyClass()
myObject.PrintList1("Red", "Blue", "Green")
myObject.PrintList2(George="Red", Sue="Blue", Zarah="Green")

要使其正常工作，还需要使方法采用self参数，如下所示：

class MyClass:
    def PrintList1(self, *args):
        for Count, Item in enumerate(args):
            print("{0}. {1}".format(Count, Item))

    def PrintList2(self, **kwargs):
        for Name, Value in kwargs.items():
            print("{0} likes {1}".format(Name, Value))

如果要将代码作为静态函数调用，则需要将staticmethod修饰符添加到类中，如下所示：

class MyClass:
    @staticmethod
    def PrintList1(*args):
        for Count, Item in enumerate(args):
            print("{0}. {1}".format(Count, Item))

    @staticmethod
    def PrintList2(**kwargs):
        for Name, Value in kwargs.items():
            print("{0} likes {1}".format(Name, Value))

MyClass.PrintList1("Red", "Blue", "Green")
MyClass.PrintList2(George="Red", Sue="Blue",Zarah="Green")