[learn Python from simple to deep] inheritance and rewriting of object-oriented class 2

One 、 Class inheritance

Inherit ： Code reuse , Subclasses get all the functions of the parent class

1. Define a class

# Defining classes 
class Animal:
# Define the properties of the class ： By construction method 
def __init__(self,name,age):
self.name=name
self.age=age
# Define the methods of the class 
def sit(self):
# Simulate the animal being ordered to sit down 
print(self.name + " is now sitting")

2. Inheritance class

class Dog(Animal): # On behalf of inheritance Animal class ,Animal Parent class ,Dog Subclass 
pass # Place holder 

jinmao=Dog("Xiaojin",5)
jinmao.name

‘Xiaojin’

jinmao.sit()

Xiaojin is now sitting

Two 、 Class

rewrite （overwrite）: If the method of the parent class cannot meet the requirements , You can override the methods of the parent class in a subclass

lass Dog(Animal):
def sit(self):
print(self.name+" is now sitting,My age is %d"%self.age)

hashiqi=Dog('Xiaoha',2)
hashiqi.name

‘Xiaoha’

hashiqi.sit()

Xiaoha is now sitting,My age is 2