在Python中按字母顺序对文本文件的内容进行排序

Question

I would like to alphabetically sort the file inside the variable 'infofile'. My current code to do this does not work, with the file remaining untouched. The program itself is a basic questionnaire, created to experiment reading and writing to files.

import time
import sys

name = input("What is your first name?").upper()

age = input("How old are you?")
while not age.isdigit():
    print("Please Only Enter Numbers.")
    age = input("How old are you?")

if int(age) <16:
    infofile = "DatabaseMinor.txt"
elif int(age) >15 and int(age) <22:
    infofile = "DatabaseYoungAdult.txt"
elif int(age) >21 and int(age) <65:
    infofile = "DatabaseAdult.txt"
else:
    infofile = "DatabaseSenior.txt"

gender = input("Are you [M]ale or [F]emale?").upper()
while gender not in {'M', 'F'}:
    print("Please Only Enter M Or F.")
    gender = str(input("Are you [M]ale or [F]emale?")).upper()

location = input("What country are you from? (UK)").upper()
while location not in {'ENGLAND', 'SCOTLAND', 'WALES', 'NORTHERN IRELAND'}:
      print("Please Only Enter A Valid Country Within The UK.")
      location = input("What country are you from?").upper()

#Compilation of inputs into a single line format
userinfo = name + " " + str(age) + " " + gender + " " + location + " " + (time.strftime("%d/%m/%Y")) + " " + (time.strftime("%H:%M:%S")) + '\n'

#Opening and writing value of the userinfo variable to the appropriate text file
file = open(infofile, 'a')
file.write(userinfo)
file.close()

file = open(infofile)
lines = file.readlines()
lines.sort()
file.close()

Thanks in advance.

Answer 1

You're forgetting to write the sorted lines back to the file:

file = open(infofile)
lines = file.readlines()
lines.sort()
for line in lines:
    file.write(line)   # <-- Write the lines back
file.close()