如何修复此使用txt文件读取和写入文件的python程序

Question

I wrote this code which is supposed to input, output and clear a file, but whenever I write to it twice in a row, the second input overrides the first does anyone know how to help?

while True:
    inorout=input("Would you like to input, output, quit or clear history?")
    if inorout.lower() == "input":
      repairs = open('repairs.txt', 'w')
      customer = input('Customer: ')
      job = input('Service: ')
      date = input("Date(dd.mm.yyyy):")

      if customer and job and date:
        repairs.write('%s, %s, %s\n' %(customer, job, date))
      else:
        print("Not applicable")

Answer 1

That's because you have opened the file to write in w (write) mode, which will start writing from start every time. You need to open the file in a+ (append mode).

Replace the line (line no: 4)

repairs = open('repairs.txt', 'w')

With:

repairs = open('repairs.txt', 'a+')

For your help, this is your full working code.

while True:
    inorout=input("Would you like to input, output, quit or clear history?")
    if inorout.lower() == "input":
      repairs = open('repairs.txt', 'a+') # <----- this line
      customer = input('Customer: ')
      job = input('Service: ')
      date = input("Date(dd.mm.yyyy):")


      if customer and job and date:
        repairs.write('%s, %s, %s\n' %(customer, job, date))
      else:
        print("Not applicable")
      repairs.close()    # <------- this line 

    elif inorout.lower() == "output":
      repairs = open('repairs.txt', 'r')
      selected=input("What customer do you select?")
      output=repairs.readlines()
      stripped_output = []
      for line in output:
        stripped_output.append(line.strip())

      for pair in stripped_output:
        if pair.split(', ')[0] == selected:
          print(pair)
        else:
          print("Customer not found.")
      repairs.close()    # <------- this line 

    elif inorout.lower() == 'quit':
      break
    elif inorout.lower() == "clear history":
      open("repairs.txt", 'w').close()
      print("Databases successfully reset")
    else:
      print('Command not found.')