Python Learning Day07

One: File operation

#Codeing:utf-8#__author__:duke#date:2018/3/4/004#Learn file operations today##读文件f = open ('Information','R', encoding='Utf-8')#opens a File object, in the form of a readdata = F.read (5)#With the Read method, the entire contents of the argument are the number of characters when no argument is given .Print(data) f.close ()#Close File###写文件f = open ('Information2','W', encoding='Utf-8')#open a File object, write the wayF.write ('Hello World!')#and use the Write methodF.write ('Duke') F.close ()#Close File###追加文件内容f = open ('Information2','a', encoding='Utf-8')#opens a File object, appendedF.write ('Hello ****!')#and use the Write methodF.write ('Duke') F.close ()#Close File#r+ mode is appended at the endf = open ('Information','r+', encoding='Utf-8')#opens a File object, in the form of a readdata = F.read (5)#With the Read method, the entire contents of the argument are the number of characters when no argument is given .Print(data) F.write ('\njoin') F.close ()#Close File#clear first, can be read after writingf = open ('Information','w+', encoding='Utf-8')#opens a File object, in the form of a readF.write ('Join')Print(F.tell ())#after finishing the cursor at the endF.seek (0)#adjust the cursor before you can readPrint(F.readline ()) F.close ()#Close File#Copying FilesF_read = open ('Information2','R', encoding='UTF-8') F_write= Open ('Information3','a', encoding='UTF-8') Num=0 forLineinchF_read:num= Num+1ifnum = = 6: Line='Hello world\n'F_write.write (line) F_write.close () f_read.close ()

Two: Methods of File objects

#Codeing:utf-8#__author__:duke#date:2018/3/4/004#Read the filef = open ('Information','R', encoding='Utf-8')#opens a File object, in the form of a readnum =0; forIinchF:#the iterator method reads the data, that is, a row to fetch a rowNum +=1ifnum = = 6: I="'. Join ([I.strip (),'III'])    Print(I.strip ()) F.close ()#Close File##tell方法f = open ('Information','R', encoding='Utf-8')#opens a File object, in the form of a readPrint(F.tell ())#Tell method read cursor positionPrint(F.read (1))Print(F.tell ()) f.seek (0)#Adjust cursor positionPrint(F.tell ())Print(F.read (1))Print(F.tell ()) F.close ()#Close FileImportTIMEF= Open ('Information2','W', encoding='Utf-8')#opens a File object, in the form of a readF.write ('Duke')#With the Read method, the entire contents of the argument are the number of characters when no argument is given .F.flush () time.sleep (10) Time.sleep (10) F.close ()#Close File#Flush MethodImportTime,sys forIinchRange (30): Sys.stdout.write ('*') Sys.stdout.flush () Time.sleep (0.1)#Truncate truncation Methodf = open ('Information2','a', encoding='Utf-8')#opens a File object, appendedF.truncate (2) F.close ()#Close File

Three: Working time (three-level menu additions and deletions to check and change)

#Codeing:utf-8#__author__:duke#date:2018/3/4/004file= Open ('Information','r+', encoding='UTF-8') Data=file.read () data=eval (data) file.close ();#For key in data:#print (key)Current_layer = data;#record your current levelParent_layers =[];#List Store Entry pathFlag =0; whileTrue: forKeyinchCurrent_layer:Print(key);#Looping the Print menuChoice = input ("[B: Return, D: Delete, a: Add, R: Modify]>>>:"). Strip ()#input, and remove extra characters in front and back of the space form    ifLen (choice) = = 0:Continue; ifChoiceinchcurrent_layer:parent_layers.append (Current_layer)#Before entering the next layer, put his first layer into the list of paths to goCurrent_layer = Current_layer[choice];#assigns the next layer to the current layer    elifChoice = ='b':        ifParent_layers:current_layer= Parent_layers.pop ();#takes out its parent layer and assigns it to the current layer        elifFlag ==1 :             Break; Else: Flag+=1Print("is already the first level, and pressing once will exit the program")    elifChoice = ='D': Value= Input ("Enter the value you want to delete:>>") Current_layer.pop (value)elifChoice = ='R': value1= Input ("Enter the value you want to modify:>>") Current_layer.pop (value1) value2= Input ("Enter the value you want to modify:>>") value2={value2: {}} current_layer.update (value2)elifChoice = ='a': Value= Input ("Enter the value you want to add:>>") Value={value:{}} current_layer.update (value)Else:#Judging Illegal input        Print("no this option ...");Print(data) file2= Open ('Information','W', encoding='UTF-8') Data=str (data) file2.write (data) file2.close ()

Python Learning Day07