先看变量可以怎么玩
age=18
x=age                    把age的内存地址赋值给x
print(age,x)>>18 18
******************************
同理，变量可以这么玩
def func():print('func run')
x=func                  注意：加括号代表的是函数体运行后的返回值
x()
print(x)func run<function func at 0x0000021DFB1D1A60>——————————————————————————————————
def func():print('func run')
x=func()
print(x)>>func run                 >>None              没有返回值  

age=18
def old_func():print("from func")def func(x):print(x)
func(age)
func(old_func)18<function old_func at 0x0000023AD58F1A60>

age=18
def old_func():print("from func")def func(x):return x
res=func(age)
print(res)
res=func(old_func)
print(res)18<function old_func at 0x000001882ACE1A60>

age=18
def old_func():print("from china")
l=[age,old_func,old_func()]
print(l)from china[18, <function old_func at 0x000001FC9BF41A60>, None]

def login():print('登录...')
def register():print('注册...')
def shopping():print('购物...')
def pay():print('支付...')
msg="""
0 退出
1 登录
2 注册
3 购物
4 支付
"""
func_dic={'4':pay,'3':shopping,'2':register,'1':login
}
while True:print(msg)choice = input('请输入您的操作：')if choice == '0':breakif choice in func_dic:func_dic[choice]()else:print('输入有误')

def func():print('from bar')
def bar():print('from func')func()
bar()

def f1():print('from f1')def f2():print('from f2')def f3():print('from f3')f3()f2()
f1()

x=000
def f1():x=111def f2():x=222def f3():def f4():# x=444    注释掉print(x)x=333f4()f3()f2()
f1()>>333

#定义闭包函数，内层函数看成是定义一个变量，函数名是变量名
def outer():a=10return a
f=outer()
print(f)def outer():def inner():        #类似a=10passreturn inner         #类似return a
f=outer()                 执行外层函数，拿到的是内层函数的内存地址
print(f)
f()

def func(x,y):print(x+y)func(1,2)

 def outter(x,y):# x=1# y=2def func():print(x+y)return funcf=outter(1,2)f()

#直接通过参数传参
def get(url):response=requests.get(url)if response.status_code == 200:print(len(response.text))
get('https://www.baidu.com')    #来一次就需要输入完整的路径，较麻烦
get('https://www.baidu.com')
get('https://www.baidu.com')
get('https://www.tmall.com')#即使指定，这是全局作用域，任何函数都能访问到都能访问到，url1='https://www.baidu.com'url2='https://www.tmall.com'get(url1)get(url1)get(url2)get(url2)
------------------------------------------------------------------------#通过闭包函数传参
def bar(url):def get():response=requests.get(url)if response.status_code == 200:print(len(response.text))return get
baidu=bar('https://www.baidu.com')    #指定好一个，下次直接使用，是绑定的关系
baidu()
baidu()
baidu()
tmall=bar('https://www.tmall.com')     #将该地址绑定给tmall
tmall()

import time
def index():print('from index')time.sleep(3)def wrapper(func):def inner():start=time.time()func()stop = time.time()print('run time %s' %(stop-start))return inner#闭包函数，f=inner的内存地址
f = wrapper(index)     #index = wrapper(index)   变量名可随意命名
f()                             #index()

def index(name,age):print('my name is %s,age is %s' %(name,age))return 1       #如果有返回值怎么拿def outer(func):      #外层函数接收的是被装饰函数名def inner(*args,**kwargs):   #内层函数接收被装饰对象需要的参数，想象执行过程res = func(*args,**kwargs)      #接收返回值并返回return res       #也就是在此处返回被装饰对象的返回值return innerindex=outer(index)
data = index('pdun',1)
print(data)my name is pdun,age is 1
1

import time
def outer(x):def inner(*args,**kwargs):s=time.time()res=x(*args,**kwargs)o=time.time()return resreturn inner@outer
def func(name):time.sleep(1)print('my name is %s' %(name))return 0func('pdun')