Python中的闭包和装饰器

闭包

def aaa(num1):
    num2 = 2
    def bbb(num3):
        he = num1 + num2 + num3
        return he
    return bbb
a = aaa(1)
print(a(1))      # 4
print(a(2))      # 5
print(a(3))      # 6
b = aaa(2)
print(b(1))      # 5
print(b(2))      # 6
print(b(3))      # 7

装饰器（被装饰函数无返回值）

import time
# 装饰器，计算被装饰函数执行所用的时间
def aaa(hanshu):
    def bbb(canshu):
        a = time.time()
        hanshu(canshu)
        b = time.time()
        c = b - a
        print(c)
    return bbb
@aaa
# 被装饰函数，计算a之前（包括a）的所有整数的和
def ccc(a):
    he = 0
    for i in range(a+1):
        he += i
    print(he)
ccc(100000000)      # 调用被装饰函数
# 运行结果
# 5000000050000000
# 5.484313726425171

装饰器（被装饰函数有返回值）

import time
# 装饰器，计算被装饰函数执行所用的时间
def aaa(hanshu):
    def bbb(canshu):
        a = time.time()
        j = hanshu(canshu)
        b = time.time()
        c = b - a
        print(c)
        return j
    return bbb
@aaa
# 被装饰函数，计算a之前（包括a）的所有整数的和
def ccc(a):
    he = 0
    for i in range(a+1):
        he += i
    return he
print(ccc(100000000))
# 运行结果
# 5.4343109130859375
# 5000000050000000