ChildClass object 没有属性栏

Question

class Foo(Baz, Qux):
    def __init__(self, bar, *args, **kwargs):
        super(Foo, self).__init__(bar=bar, *args, **kwargs)

class Baz:   
    def __init__(self, bar, *args, **kwargs):
        self.bar = bar

这是我的 classes 的结构，Foo class 继承了 Baz class。但是，当我尝试运行代码时，出现以下错误 Foo object has no attribute bar

据我了解，super(childclass, self).__init__(parent, attributes) 也应该初始化 parent class。为什么 bar 也应该出现在 child class 中？

我按照以下堆栈答案来实现这个：Calling parent class __init__ with multiple inheritance, what's the right way?

编辑

class Qux:   
    def __init__(self, xyz, *args, **kwargs):
        self.xyz = xyz
    
    def print_barqux(self):
        print(self.xyz)
        
class Baz:   
    def __init__(self, bar, *args, **kwargs):
        self.bar = bar
        
class Foo(Baz, Qux):
    def __init__(self, bar, xyz, *args, **kwargs):
        super(Foo, self).__init__(bar=bar, xyz=xyz)

    def printbar(self):
        super(Foo, self).print_barqux()
        
        
foo = Foo(bar="abcd", xyz="abcdef")
print(foo.printbar())

输出：

Traceback (most recent call last):
  File "./prog.py", line 21, in <module>
  File "./prog.py", line 17, in printbar
  File "./prog.py", line 6, in print_barqux
AttributeError: 'Foo' object has no attribute 'xyz'

使用代码添加错误堆栈跟踪

Answer 1

每个 class 必须调用 super.__init__:

class Qux:   
    def __init__(self, xyz, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.xyz = xyz
    
    def print_barqux(self):
        print(self.xyz)
        
class Baz:   
    def __init__(self, bar, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.bar = bar
        
class Foo(Baz, Qux):
    def __init__(self, bar, xyz, *args, **kwargs):
        super().__init__(bar=bar, xyz=xyz)

    def printbar(self):
        super().print_barqux()
        
        
foo = Foo(bar="abcd", xyz="abcdef")
print(foo.printbar())

ChildClass object 没有属性栏

ChildClass object has no attribute bar

python

oop

inheritance

multiple-inheritance

python-2.7