定义一个类：Person类, name , age
person = Person("", 19)

print(person) => “My name is xxx, age is xx”
bool(person) => 返回False
len(person) => 1024
person2 = Person("", 20)
person == person2 #如果两个年龄相等返回True, 不相等返回False
person < person2 #如果person年龄> person2的年龄，返回False, 否则 返回True

person + person2: 返回: person的名字和person2的名字

class person():
    def __init__(self,name,age):
        self.name = name
        self.age = age
    def print(self):
        print(f'my name is {person.name}, age is {person.age}')
    def __bool__(self):
        return  False
    def __len__(self):
        return 1024
    def __eq__(self, other):
        if  self.age == other.age:
            return True
        else:
            return False
    def __gt__(self, other):
        if self.age > other.age:
            return False
        else:
            return True
    def __add__(self, other):
        return self.age + other.age

zhangsan = person('zhangsan', 20)
lisi = person('lisi', 22)

print(zhangsan)
bool(zhangsan)
len(zhangsan)
print(zhangsan == lisi)
print(zhangsan < lisi)
print(zhangsan + lisi)

定义一个装饰器：计算函数执行时间: 使用模块time

time.sleep(2)
#计算函数运行时间；
import time
print(time.time())
time.sleep(2)
print(time.time())

import time
a = time.time()

def fun_a(aaa):
    def fun2():
        print('I',end='\t')
        aaa()
        print('YOU')
    return fun2

@fun_a
def fun():
    print('LOVE',end='\t')

fun()
time.sleep(5.20)
b = time.time()
print(f"{b - a:4.3}")