Python学习

Decorater

import time
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

def prime_nums():
	t1 = time.time()
	for i in range(2,10000):
		if is_prime(i):
			print(i)
	t2 = time.time()
	print(t2-t1)
prime_nums()

如果使用time函数的地方比较多，每次都这样写会比较麻烦，而且获取时间的逻辑和别的代码逻辑放到一起比较混乱。
装饰器如何使用？

import time


def display_time(func):
    def wrapper():
        t1 = time.time()
        func()
        t2 = time.time()
        print(t2 - t1)

    return wrapper


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

@display_time
def prime_nums():
    for i in range(2, 10000):
        if is_prime(i):
            print(i)


prime_nums()

带返回值

def display_time(func):
	def wrapper():
		t1 = time.time()
		result = func()
		print("Total time: {:.4} s".format(t2-t1))
		return result
	return wrapper        

函数带有参数的情况

def display_time(func):
	def wrapper(*args):
		t1 = time.time()
		result = func(*args)
		print("Total time: {:.4} s".format(t2-t1))
		return result

*args表示有多个参数

赏

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