Python Learning Day9

Yesterday review:

file processing    opens the file open        (' path ', ' open mode ',' Specify the encoding method ' )        Open mode R w a r+ w+ A + b            r+ open File Direct write and read re-write        encoding method--utf-8     operation file 
     read one-time read readlines One-time read readline one line            read                don't know where to end                video pictures rb bytes read for loops in bytes            -Best!!!        writes        The write cursor--the file pointer            seek _ specifies that the cursor moves to a location tell            _ Gets the current position of the cursor            truncate _ intercept file    close file        Close

Today's content: functions

#function Code Exercises#s = ' dsffse '#def my_len (): #定义之后, can be called from anywhere. #i = 0#For K in S:#I +=1#print (i)#length = My_len ()#print (length)#importance of the return value#def my_len ():#i = 0#For K in S:#i + = 1#return I#length = My_len ()#print (length)#three cases of return value    #no return value---return none        #do not write return        #write return only to End Function run        #return None---not used    #returns a value        #can return any data type        #as soon as you return, you can receive        #If there are multiple return, only the first one is executed    #return multiple values        #receive with an equal amount of variables        #accept with a variable, get a tuple#def func ():#L = [' Received ', ' King boss ']#For i in L:#print (i)#if i = = ' King boss ':#return None#print (' = ' *10)#ret = func ()#print (ret)#def func ():#return {' K ': ' V '}#Print (func ())#def func ():#return#Res=func ()#Print (res)#def My_len (s):#i = 0#For K in S:#i + = 1#return I#ret = My_len (' Dasdasds ')#print (ret)#ret = My_len ([1,2,3,4,5])#print (ret)#parameter order: Position parameter, *args, default parameter, **kwargs#There are two types of dynamic parameters:                #*args: Received by the value of the location parameter, organized into a tuple                #**kwargs: Received by keyword, organized into a dictionary of the value of the parameter                #*args must be before **kwargs#def sum (*args):#n = 0#For i in args:#n + = i#return n#print (sum ())#Print (sum (1,2,3,4))#Print (sum (1,2,3,4,5))##def func (**kwargs):#print (Kwargs)#func (a = 1,b = 2)#def func (*args,default = 1,**kwargs):#print (Args,kwargs)#func (1,2,3,4,5,6,7,default=2,a= ' s ', b= ' s ')##def func (*args):#print (args)##func (1,2,3,4,5)#l=[1,2,3,4,5]#func (*l) #站在实参的角度上, adding * to a sequence, is to break the sequence in order#def func (**kwargs):#print (Kwargs)#func (a=1,b=2)#d = {' A ': 1, ' B ': 2}#func (**d)##函数的注释## def func ():#     """#Functions of the function#parameter one:#parameter two:#: Return: What is returned#     """

Python Learning Day9