类和数据类型

一、类与数据类型

• python3中统一了类与类型的概念，类就是类型

class Foo:
    pass


obj = Foo()
print(type(obj))
# <class '__main__.Foo'>
lis = [1, 2, 3]
lis2 = [4, 5, 6]
print(type(lis))
# <class 'list'>

• lis和lis2都是实例化的对象，因此lis使用append方法和lis2无关

lis.append(7)
print(lis)
# [1, 2, 3, 7]
print(lis2)
# [4, 5, 6]

二、list.append()方法原理

class Student:
    school = 'oldboy'

    def __init__(self, name, age, gender):
        self.name = name
        self.age = age
        self.sex = gender

    def choose_course(self, name):
        print(f'{name} choosing course')


stu1 = Student('randy', 18, 'male')
stu1.choose_course(1)  # Student.choose_course(stu1, 1)

# 1 choosing course

Student.choose_course(stu1, 1)

# 1 choosing course

lis = [1, 2, 3]  # lis = list([1,2,3])
print(type(lis))
<class 'list'>
lis.append(4)  # list.append(lis,4)
print(lis)
[1, 2, 3, 4]
list.append(lis, 5)
print(lis)
[1, 2, 3, 4, 5]