python设计模式1:python中类的继承

In [1]: class Employee:
   ...:     def __init__(self,name,salary=0):
   ...:         self.name = name
   ...:         self.salary = salary
   ...:         

In [2]: class Designer(Employee):
            def __init__(self,name):
   ...:         self.name = name
   ...:                 

In [3]: d = Designer("alex")

In [4]: d.salary
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-4-c8934453b0a8> in <module>()
----> 1 d.salary

AttributeError: ‘Designer‘ object has no attribute ‘salary‘

In [5]: e = Employee(‘alex‘)

In [6]: e.salary
Out[6]: 0