Question

我在下面的程序中得到了RecusionError，我无法找出原因。请求专家帮助。

从Derived类调用Base类的方法foo导致 RecusionError

BaseKill():
    def foo(self):
        print('what is wrong with jpython')
        return self.bar()
    def bar(self):
        print('just chill bar')
        return None

class Derived(BaseKill):
    def bar(self):
        print('I am bar')
        self.foo()
        self.hello()
    def hello(self):
        print('say Hi')


if __name__== '__main__':
    print('what')
    b=BaseKill()
    b.foo()
    c = Derived()
    c.bar()

Answer 1

执行class Derived(BaseKill) class Derived()现在“继承”来自class BaseKill的方法。

包括foo()和bar()。

但是，您bar()中定义的class Derived()优先于“已继承的bar()”

基本上这与执行以下操作相似

class Derived():
    def foo(self):
        print('what is wrong with jpython')
        return self.bar()    
    def bar(self):
        print('I am bar')
        self.foo()
        self.hello()
    def hello(self):
        print('say Hi')


if __name__== '__main__':
    print('what')
    c = Derived()
    c.bar()

通过此代码，您可以清楚地看到bar()正在呼叫foo()，而bar()又会再次呼叫print。这是一个无限/递归。

您看到的错误是正确的。

在原始代码中，您可以添加一些self语句来获取print(self.__class__.__name__)所代表的类的名称，例如@staticmethod。这可以帮助您进一步了解类继承。

您可能希望BaseKill.bar()查看class BaseKill(): def foo(self): print('what is wrong with jpython') return BaseKill.bar() @staticmethod def bar(): print('just chill bar') return None class Derived(BaseKill): def bar(self): print('I am bar') self.foo() self.hello() def hello(self): print('say Hi') if __name__== '__main__': print('what') b=BaseKill() b.foo() c = Derived() c.bar()，但这会更改功能，因此请确保彻底测试以确保符合您的要求：

foo()

More information about @staticmethod here

或者，您可以对BaseKill中的class BaseKill(): def foo(self): print('what is wrong with jpython') return BaseKill.bar(self)执行以下操作：

profiles

Answer 2

Leason学会了：在调用同一类的方法时，在它们前面使用它的名字，比如BaseKill.bar（self） 来防止由于覆盖方法而导致的错误

BaseKill():
        def foo(self):
            print('what is wrong with jpython')
            #return self.bar() ----Error 'self' referred to Calling class
            return BaseKill.bar(self) #referred to same class method

        def bar(self):
            print('just chill bar')
            return None

    class Derived(BaseKill):
        def bar(self):
            print('I am bar')
            self.foo()
            self.hello()
        def hello(self):
            print('say Hi')


    if __name__== '__main__':
        print('what')
        b=BaseKill()
        b.foo()
        c = Derived()
        c.bar()

RecursionError：在对对象进行pickle时超出了最大递归深度

2 个答案: