Python开发——面向对象【类、实例】

类

 # class Chinese(object):
 class Chinese:
     '''
     类的说明性文档
     '''
     pass
 
 print(Chinese)  # <class '__main__.Chinese'>
 
 # 类的实例化：类名+小括号，到底做了什么？
 p1 = Chinese()
 print(p1)       # <__main__.Chinese object at 0x0568C2B0>

类的属性操作

 class Chinese:
     country = 'China'
     def __init__(self,name):
         self.name = name
     def play(self):
         print("玩耍")
     def sing(self):
         print("唱歌")
 
 print(Chinese)      # <class '__main__.Chinese'>
 # 打印类的数据字典
 print(Chinese.__dict__)
 
 #################——数据属性——######################
 # 查看
 print(Chinese.country)  # China
 # 修改
 Chinese.country = '中国'
 print(Chinese.country)  # 中国
 # 增加
 Chinese.dang = '党'
 print(Chinese.dang)
 # 删除
 # print(Chinese.__dict__)
 del Chinese.dang
 # 打印类的数据字典
 # print(Chinese.__dict__)
 
 #################——函数属性——######################
 def eat(self):
     print("吃吃吃")
 def eat123(self):
     print("吃吃吃123")
 # 增加
 Chinese.eat = eat
 # 查看
 print(Chinese.eat)      # <function eat at 0x04D0C8E8>
 # 打印类的数据字典
 # print(Chinese.__dict__)
 # 修改
 Chinese.eat = eat123
 print(Chinese.eat)      # <function eat123 at 0x04DEC810>
 # 删除
 del Chinese.eat
 # print(Chinese.__dict__)

实例的属性操作

 class Chinese:
     country = 'China'
     def __init__(self,name):
         self.name = name
     def play(self):
         print("玩耍")
     def sing(self):
         print("唱歌")
 
 p1 = Chinese('yuan')
 print(p1)           # <__main__.Chinese object at 0x05079CD0>
 # 打印实例的数据字典【即init中的】
 print(p1.__dict__)  # {'name': 'yuan'}
 
 #################——数据属性——######################
 # 查看
 print(p1.name)      # yuan
 # 增加
 p1.age = 18
 print(p1.age)       #
 # 打印实例的数据字典
 print(p1.__dict__)  # {'name': 'yuan', 'age': 18}
 
 #不要修改底层的属性字典
 # p1.__dict__['sex']='male'
 # print(p1.__dict__)
 # print(p1.sex)
 
 # 修改
 p1.age = 23
 print(p1.age)       #
 print(p1.__dict__)  # {'name': 'yuan', 'age': 23}
 # 删除
 del p1.age
 print(p1.__dict__)  # {'name': 'yuan'}
 
 #################——函数属性——######################
 # 实例没有函数属性
 # 类的属性修改会直接体现到实例
 
 def eat(self):
     print("吃吃吃")
 # 增加
 p1.eat = eat
 # 查看【忘记吧】
 # p1.eat("###")    # 容易出错
 # p1.eat(p1)

类与实例

 country = "中国****"
 class Chinese:
     country = 'China'
     def __init__(self,name):
         self.name = name
         print("--->", country)  # ---> 中国****
     def play(self):
         print("玩耍")
     def sing(self):
         print("唱歌")
 
 p1 = Chinese('yuan')
 # 打印实例的数据字典
 print(p1.__dict__)  # {'name': 'yuan'}
 # 【当实例的数据字典没有时】访问类的数据字典
 print(p1.country)
 
 p1.country = "中国"
 # 打印实例的数据字典
 print(p1.__dict__)  # {'name': 'yuan', 'country': '中国'}
 # 访问实例的数据字典
 print(p1.country)   # 中国
 
 # 访问类的数据字典
 print(Chinese.country)  # China
 # 初始化时【country与p1.country、Chinese.country的区别】
 p2 = Chinese('Lucy')    # 初始化时