Python3 adds, deletes, modifies, and views the local TXT file.

Since it is a beginner, if the code is insufficient, please point out!

This blog records my programming journey, records what I have learned, and shares what I have learned!

This is one of my homework.

First analyze the requirements:

1. Create a TXT file to store account and password
2. Realize the functions of adding, deleting, modifying and viewing files

analysis of idea:

1. Write a menu of choices first
2. List the custom functions we want to write
3. The main method to realize the functions of adding, deleting, modifying and viewing is to read the file and return a list, then add, delete, modify the list, and finally write the list to the file.

 

1  def jia(LIST):           # 1 Add function 
2      print ( ' Space and carriage return to exit! ' )
 3      while True:
 4          S = input( ' Enter account number: ' )
 5          if (S== '  ' ):
 6              break 
7          S2=input( ' Enter password: ' )
 8          LIST.append(S+ '     ' +S2+ ' \n ' )
 9          with open( ' wj-4.txt ', ' w ' )as F:
 10              F.writelines(LIST)
 11  
12  def cha(LIST):              # 2 view function 
13      print ( ' The content of the file is below: ' )
 14      for i in LIST:
 15          print (i.strip ( ' \n ' ))
 16      input( " Press any key to return to the menu! " )
 17      cai(LIST)
 18  
19  def shan(LIST):              # 3 delete function 
20      print( ' Enter -1 to exit! ' )
 21      while True:
 22          R = int(input( ' Please enter the delete number: ' ))
 23          if (R==-1 ):
 24              break 
25          del LIST[R - 1 ]
 26          with open( ' wj-4.txt ' , ' w ' )as F:
 27              F. writelines(LIST)
 28  
29  def gai(LIST):                   # 5 Modify the function 
30      print ( ' Enter -1 to exit!' )
 31      while True:
 32          R = int(input( ' Please enter the modified number: ' ))
 33          if (R==-1 ):
 34              break 
35          R2 = input( ' Enter the modified character: ' )
 36          del LIST[R - 1 ]
 37          LIST.insert(R - 1 , R2)
 38          print (LIST)
 39  
40  def du():             #Read file function 
41      with open( ' wj-4.txt ' , ' r' )as f:
 42          LIST = f.readlines()
 43      return LIST
 44  
45  def cai(LIST):               #Menu function 
46      while True:
 47          print ( ' Menu selection:\n(1)Add function\n(2) View function\n(3)Delete function\n(4)Modify function\n(5)Exit ' )
 48          A=int(input( ' Please input: ' ))
 49          if (A==1 ):
 50              jia( LIST)
 51          elif (A==2 ):
 52              cha (LIST)
 53          elif(A==3 ):
 54              shan(LIST)
 55          elif (A==4 ):
 56              gai(LIST)
 57          elif (A==5 ):
 58              print ( ' Exit successfully!\nWelcome next time! ' )
 59              break 
60          else : print ( ' Please enter the selection correctly! ' )
 61  
62  if  __name__ == ' __main__ ' :
 63      try :
 64          LIST = du()   #return list 
65cai          (LIST) #Menu      66 except : print ( ' An unknown error occurred! ' )
     

Test chart:

This content mainly assesses familiarity with lists and files.