Python全栈之路Day19

def f1():
    x = 1
    print(‘----->f1 ‘,x)
    def f2():
        x = 2
        print(‘---->f2 ‘,x)
        def f3():
            x = 3
            print(‘--->f3 ‘,x)
        f3()
    f2()
f1()        >>>----->f1  1;---->f2  2;--->f3  3

def foo():
    print(‘foo‘)

print(foo)

f = foo
print(f)

def foo():
    print(‘foo‘)

def bar(func):        >>><function foo at 0x00000000003E3F28>;foo
    print(func)
    func()

bar(foo)

def foo():
    print(‘foo‘)

def bar(func):
    print(func)
    return func

f = bar(foo)
print(f)

def add():
    print(‘==========function add‘)

def    delete():
    print(‘==========function delete‘)

def search():
    print(‘==========function search‘)
def change():
    print(‘==========function change‘)

def tell_msg():
    msg = ‘‘‘
    delete:删除
    add:添加
    search:查询
    change:更改
    ‘‘‘
    print(msg)

cmd_list = {
    ‘add‘:add,
    ‘delete‘:delete,
    ‘search‘:search,
    ‘change‘:change
}

while True:
    tell_msg()
    choice = input(‘please input your choice: ‘).strip()
    cmd_list[choice]()

x =1

def f1():
    x = 1000
    def f2():
        print(x)
    return f2

f = f1()
f()
print(f.__closure__[0])
print(f.__closure__[0].cell_contents)

>>><1000
>>><cell at 0x0000000002177498: int object at 0x0000000001DC9EF0>
>>>1000

from urllib.request import urlopen
def f1(url):
    def f2():
        print(urlopen(url).read())
    return f2

baidu = f1(‘http://www.baidu.com‘)        #爬网页
baidu()