类

class Student:name = Nonegender = Nonenationality = Nonenative_place = Noneage = Nonedef say_hi(self):print(self.name)def dowork(self,work):print(f"{self.name} {work}")
student1 = Student()
student1.name = "xxx"
student1.gender = "男"
student1.nationality = "中国"
student1.native_place = "山东省"
student1.age = 31
print(student1.name)
student1.dowork("codding")
student1.say_hi()

构造方法

#构造方法
class Animal:name = Noneage = Nonedef __init__(self,name,age):self.name = nameself.age = ageprint("animal init")dog = Animal(name="dog",age=11)

魔术方法

#构造方法
class Animal:name = Noneage = Nonedef __init__(self,name,age):self.name = nameself.age = ageprint("animal init")# 输出打印def __str__(self) -> str:return f"{self.name} age={self.age}"#比较 小于 大于def __lt__(self, other):return self.age < other.age#小于等于def __le__(self, other):return self.age <= other.age#等于 ==def __eq__(self, __value: object) -> bool:return self.age == other.agedog = Animal(name="dog",age=11)
print(dog)
dog2 = Animal(name="dog2",age=12)
print(dog > dog2)

  封装

私有成员变量变量名以__(双下划线开头)

私有成员方法方法名以__(双下划线开始)

class Phone:#私有成员变量__current_voltage = 0#私有成员函数def __keep_single_core(self):print("single")def callby_5g(self):if self.__current_voltage >= 1:print("__current_voltage >= 1")else:self.__keep_single_core()print("__current_voltage < 1")phoe = Phone()
phoe.callby_5g()

继承

单继承

#构造方法
class Animal:name = Noneage = Nonedef __init__(self,name,age):self.name = nameself.age = ageprint("animal init")# 输出打印def __str__(self) -> str:return f"{self.name} age={self.age}"#比较 小于 大于def __lt__(self, other):return self.age < other.age#小于等于def __le__(self, other):return self.age <= other.age#等于 ==def __eq__(self, __value: object) -> bool:return self.age == other.agedog = Animal(name="dog",age=11)
print(dog)
dog2 = Animal(name="dog2",age=12)
print(dog > dog2)class Cat(Animal):kind = Nonedef color(self):print("white_yellow")cat1 = Cat(name="波斯猫",age=11)
cat1.kind = "xxxxx"
cat1.color()

多继承

复写父类方法或变量

类型注解

多态

统一行为不同对象的不同表现形式