面向对象

1. 类

# 类
class Person(object):  # object 基类
    pass


# 创建对象（类的实例化）
student = Person()
print(type(student))  # <class '__main__.Person'>
print(isinstance(student, object))
print(isinstance(student, Person))

2. 实例属性

# 实例属性
class Person(object):
    def __init__(self, name, age, address):
        self.name = name
        self.age = age
        self.address = address


student = Person('孙笑川', 33, '成都')
student.job = '主播'
print(student.__dict__)  # 获取实例的所有属性

3. 类属性

# 类属性
class Person(object):
    index = 0  # 类属性

    def __init__(self, name, age, address):
        self.name = name
        self.age = age
        self.address = address
        Person.index += 1
        if age < 0 or age > 100:
            raise Exception('年龄有误，请检查！')


try:
    student = Person('孙笑川', 33, '成都')
    print(student.__dict__)
    print('第%d个用户' % Person.index)

    student1 = Person('刘波', 30, '湖北')
    print(student1.__dict__)
    print('第%d个用户' % Person.index)
except Exception as e:
    print(e)

4. 实例方法

# 实例方法
class Person(object):
    index = 0  # 类属性

    def __init__(self, name, age, address):
        self.name = name
        self.age = age
        self.address = address
        Person.index += 1
        # print('第%d个用户' % Person.index)

    # 实例方法
    def say_hello(self):
        print('大家好，我是%s' % self.name)


try:
    student = Person('孙笑川', 33, '成都')
    # print(student.__dict__)
    student.say_hello()

    student1 = Person('刘波', 30, '湖北')
    # print(student1.__dict__)
except Exception as e:
    print(e)

5. 类方法

# 类方法
class Person(object):
    index = 0  # 类属性

    def __init__(self, name, age, address):
        self.name = name
        self.age = age
        self.address = address
        Person.index += 1
        if age < 0 or age > 100:
            raise Exception('年龄有误，请检查！')

    # 实例方法
    def say_hello(self):
        print('大家好，我是%s' % self.name)

    # 类方法
    @classmethod
    def get_user_no(cls):
        print('第%d个用户' % cls.index)


try:
    student = Person('孙笑川', 33, '成都')
    # print(student.__dict__)
    student.say_hello()

    student1 = Person('刘波', 30, '湖北')
    # print(student1.__dict__)
    Person.get_user_no()
except Exception as e:
    print(e)

6. 静态方法

# 静态方法
class Person(object):
    index = 0  # 类属性

    def __init__(self, name, age, address):
        self.name = name
        self.age = age
        self.address = address
        Person.index += 1
        if age < 0 or age > 100:
            raise Exception('年龄有误，请检查！')

    # 实例方法
    def say_hello(self):
        print('大家好，我是%s' % self.name)

    # 类方法
    @classmethod
    def get_user_no(cls):
        print('第%d个用户' % cls.index)

    # 静态方法
    @staticmethod
    def is_valid(**kwargs):
        if kwargs['token'] == '123456':
            return True
        else:
            print('前置校验失败')
            return False


try:
    check_key = {'token': '123456'}
    if Person.is_valid(**check_key):
        student = Person('孙笑川', 33, '成都')
        # print(student.__dict__)
        student.say_hello()

        student1 = Person('刘波', 30, '湖北')
        # print(student1.__dict__)
        Person.get_user_no()
    else:
        print('创建用户失败')
except Exception as e:
    print(e)

7. 继承

# 继承
class Person(object):
    index = 0  # 类属性

    def __init__(self, name, age, address):
        self.name = name
        self.age = age
        self.address = address
        Person.index += 1
        if age < 0 or age > 100:
            raise Exception('年龄有误，请检查！')

    # 实例方法
    def say_hello(self):
        print('大家好，我是%s' % self.name)

    # 类方法
    @classmethod
    def get_user_no(cls):
        print('第%d个用户' % cls.index)

    # 静态方法
    @staticmethod
    def is_valid(**kwargs):
        if kwargs['token'] == '123456':
            return True
        else:
            print('前置校验失败')
            return False


class People(Person):

    # 重写父类的 say_hello 方法
    def say_hello(self):
        print('大家好，我是%s，我来自%s' % (self.name, self.address))


try:
    check_key = {'token': '123456'}
    if Person.is_valid(**check_key):
        student = Person('孙笑川', 33, '成都')
        # print(student.__dict__)
        student.say_hello()

        student1 = People('刘波', 30, '湖北')
        # print(student1.__dict__)
        student1.say_hello()
    else:
        print('创建用户失败')
except Exception as e:
    print(e)

8. 多态

# 多态
class Animal(object):
    def say(self):
        print('Animal Say...')


class Dog(Animal):
    def say(self):
        print('汪汪汪...')


class Cat(Animal):
    def say(self):
        print('喵喵喵...')


animal = Animal()
animal.say()

dog = Dog()
dog.say()

cat = Cat()
cat.say()

9. 封装

# 封装
class Person(object):
    def __init__(self, name, age, address):
        # self._name = name  # 受保护的变量
        self.__name = name  # 私有变量
        self.__age = age
        self.__address = address
        if not isinstance(age, int) or age < 0 or age > 100:
            raise Exception('年龄有误，请检查！')

    """
    把函数当作变量使用
    @property
    def 变量名(self):  # 获取变量 get

    @变量名.setter
    def 变量名(self, 变量名):  # 设置变量 set
    """

    @property
    def name(self):
        return self.__name

    @name.setter
    def name(self, name):
        self.__name = name

    @property
    def age(self):
        return self.__age

    @age.setter
    def age(self, age):
        if not isinstance(age, int) or age < 0 or age > 100:
            raise Exception('年龄有误，请检查！')
        else:
            self.__age = age

    @property
    def address(self):
        return self.__address

    @address.setter
    def address(self, address):
        self.__address = address


try:
    student = Person('孙笑川', 33, '成都')
    print(student.name)

    # 修改属性
    student.name = '刘波'
    print(student.__dict__)
except Exception as e:
    print(e)