全局变量与局部变量

局部变量只在函数里起作用，全局变量在整个函数里起作用
def logger ():
    '日志功能'
    pass
def home ():
    logger()
    print('home')
def index():
    logger()
    print('index')

函数与调用函数
name='cat'

def change_name():
    name='dog'
    print('my name is ',name)
change_name()

修改全局变量用 global ...
name='cat'

def change_name():
    global name
    name='dog'
    print('my name is ',name)
change_name()