Python類方法重載

Question

如何重載類方法？ 我失敗：

class D(object): 
    def create(self): 
     foo = 100 
     bar = 'squirrels' 
     baz = 'I have %d insane %s in my head.' % (foo, bar) 
     return baz  

class C(D): 
    def create(self): 
     super(C, self).create() 
     baz = 'I have %s cute %s in my yard.' % (self.foo, self.bar) 

C().create() 

回溯是：

AttributeError: 'C' object has no attribute 'foo' 

Answer 1

您已嘗試將局部變量用作類屬性。嘗試執行以下更改：

class D(object): 
    def create(self): 
     self.foo = 100 
     self.bar = 'squirrels' 
     baz = 'I have %d insane %s in my head.' % (self.foo, self.bar) 
     return baz 

class C(D): 
    def create(self): 
     super(C, self).create() 
     print self.foo 
     self.baz = 'I have %s cute %s in my yard.' % (self.foo, self.bar) 

C().create() 

Answer 2

在D.create你不設置self，這意味着變量foo是函數的局部變量的變量。

class D(object): 
    def create(self): 
     self.foo = 100 
     self.bar = 'squirrels' 
     self.baz = 'I have %d insane %s in my head.' % (self.foo, self.bar) 
     return self.baz