Python Xiaobai's growth diary day 5 function local variable recursive higher-order function

def name1(): #def defines the function name is the function name
 '''file comment''' # Note that this step is a good habit, usually write
 print ( 'in the name1' )
     return 0
 def name2():
     print ( 'in the name2' )
     #If no return is added, the result of printing is none
 x=name1()        
y=name2()
print('from name1 return is %s'%x)
print('from name2 return is %s'%y)

import time #Import module
 def logger(): #The logger defines a logger as the following with can be used multiple times
 #It is     more convenient to use when there are multiple data
     time_format= '%Y-%m-%d %X' # time_forma defines your time format Y year m month d day X hours minutes seconds
     time_current=time.strftime(time_format )
     with open ( 'a.txt' , 'a+' ) as a:
        a.write('%s end action 哈哈 \n'%time_current   )
def test1():
    print('test1 starting action...')
    logger()
def test2():
    print('text2 starting action...')
    logger()
def test3():
    print('text3 starting action...')
    logger()
test1()
test2 ()
test3()

Reuse of logger code

def name1():
    print('in the  name1')

def name2():
    print('in the  name2')
    return 0
def name3():
    print('in the  name3')
    return 1,'han',['bin','long'],{1:2}
x=name1()
y=name2()
z=name3()
print (x)
 print (y)
 print (z) #finally returns a composite tuple

def name1(x,y):
    print(x)
    print(y)
name1( 1 , 3 ) #If it is not written in ( ), an error will be reported. The number of parameters
 #def in ( ) should correspond to the number in ( ) in the last name1
 def name2(x,y):
     print (x )
     print (y)
x= 1
 y= 2
 name2( y = 2 , x = 1 ) # has nothing to do with the position of the formal parameter
 # Note () can be written like this (3, y=2) but not (y=2, 3) no matter how many Quantity y=? to last

def name(x,y=2):
    print(x)
    print(y)

name(1)
#默认参数特点：调用函数的时候，默认参数非必须传递
#用途：1.默认安装2.连接数据库

#*args:接受N个位置参数，转换成元组形式
# def test(*args):
#     print(args)
# test(1,2,3,4,5,5)
# test(*[1,2,4,5,5])
# test(1,1,1,1,1,1)#  args=tuple([1,2,3,4,5])

# def test1(x,*args):
#     print(x)
#     print(args)
#
# test1(1,2,3,4,5,6,7)


#**kwargs：接受N个关键字参数，转换成字典的方式
# def test2(**kwargs):
#     print(kwargs)
#     print(kwargs['name'])
#     print(kwargs['age'])
#     print(kwargs['sex'])
# test2(name='alex',age=8,sex='F')
# test2(**{'name':'alex','age':8,'sex':'F'})


# def test3(name,**kwargs):
#     print(name)
#     print(kwargs)
# test3('alex',age=18,sex='m')

# def test4(name,age=18,**kwargs):
#     print(name)
#     print(age)
#     print(kwargs)
# test4('alex',age=34,sex='m',hobby='tesla')

def test4(name,age=18,*args,**kwargs):
    print(name)
    print(age)
    print(args)
    print(kwargs)
    logger("TEST4")
def logger(source):
    print("from %s" %  source)
test4('alex',age=34,sex='m',hobby='tesla')

#局部变量  只改变局部的值
def change_name(name):
    global school  #globe局部变量
    school = "Mage Linux"
    print("before change",name,school)
    name ="Alex li" #这个函数就是这个变量的作用域
    age =23
    print("after change",name)
name=('hanbinlong')
change_name(name)
print(name)

def calc(n):
    print(n)
    if int(n/2) >0:
        return calc( int(n/2) )
    print("->",n)


calc(10)

递归特性：

1 必须有一个明确的结束条件

2每次进入一个更深的递归中问题模式的数量要有一定的减少

def add(a,b,f):
    return f(a)+f(b)

res = add(3,-6,abs)
print(res)

Python Xiaobai's growth diary day 5 function local variable recursive higher-order function

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