装饰器

1）没有返回值的装饰器

import time

def decorator_fun(fun_dec):
    def wrapepr():
        t1 = time.time()
        fun_dec()
        t2 = time.time()
        print(t1-t2)
    return wrapepr

def is_prime(num):
    if num<2:
        return False
    elif num == 2:
        return True
    else:
        for i in range(2,num):
            if num%i==0:
                return False
        return True

@decorator_fun
def prime_nums():
    """
    引用装饰器，等同于 prime_nums = decorator_fun(prime_nums)
    :return:
    """
    for i in range(2,10000):
        if is_prime(i):
            print(i)

prime_nums()
2）有返回值的装饰器

import time

def decorator_fun(fun_dec):
    def wrapepr():
        t1 = time.time()
        count = fun_dec()
        t2 = time.time()
        print("Total time:{:.4}s".format(t1-t2))
        return count
    return wrapepr

def is_prime(num):
    if num<2:
        return False
    elif num == 2:
        return True
    else:
        for i in range(2,num):
            if num%i==0:
                return False
        return True

@decorator_fun
def count_prime_nums():
    """
    引用装饰器，等同于 prime_nums = decorator_fun(prime_nums)
    :return:
    """
    count = 0
    for i in range(2,10000):
        if is_prime(i):
            count+=1
    return count

count = count_prime_nums()
print(count)
3）有参数的装饰器

import time

def decorator_fun(fun_dec):
    # 运行fun_dec的时候需要运行那些内容
    # def wrapepr(max_num):
    def wrapepr(*args):
        t1 = time.time()
        # count = fun_dec(max_num)
        count = fun_dec(*args)
        t2 = time.time()
        print("Total time:{:.4}s".format(t1-t2))
        return count
    return wrapepr

def is_prime(num):
    if num<2:
        return False
    elif num == 2:
        return True
    else:
        for i in range(2,num):
            if num%i==0:
                return False
        return True

@decorator_fun
def count_prime_nums(max_num):
    """
    引用装饰器，等同于 prime_nums = decorator_fun(prime_nums)
    :return:
    """
    count = 0
    for i in range(2,max_num):
        if is_prime(i):
            count+=1
    return count

count = count_prime_nums(1000)
print(count)