Change text in file with Python

Question

def false_to_true():
    name = input("Input name: ")
    file=open("users.txt","r")
    lines = file.readlines()
    file.close()
    for line in lines:
        username, lel, type = line.split("/")
        while name == username:
            name = input("input name again: ")
    tip = True
    with open("users.txt", "w") as users:
        users.write(str(red))

#
#I do not know how to perform a given modification and enrollment into place in #the text.
#
#I wont to change word False to True for username i input.
#I have this text in file users:
#Marko123/male/False
#Mimi007/female/False
#John33/male/False
#Lisa12/female/False
#Inna23/female/False
#Alisa27/female/False

I won't to change word False to True for username I input.

I have this text in file users:

Marko123/male/False
Mimi007/female/False
John33/male/False
Lisa12/female/False
Inna23/female/False
Alisa27/female/False

score 1 · Answer 1 · answered Jan 04 '16 at 00:05

You can just use the csv library and forget about string manipulation:

import csv

def false_to_true():
    #read from user.txt file into list(data)
    with open('users.txt', 'r') as userfile:
        data = [row for row in csv.reader(userfile,
                                          delimiter="/",
                                          quoting=csv.QUOTE_NONE)]
    while True:
        #waiting for input until you enter nothing and hit return
        username = input("input name: ")
        if len(username) == 0:
            break
        #look for match in the data list
        for row in data:
            if username in row:
                #change false to true
                row[2] = True
                #assuming each username is uniqe break out this for loop
                break

    #write all the changes back to user.txt
    with open('users.txt', 'w', newline='\n') as userfile:
        dataWriter = csv.writer(userfile,
                                delimiter="/",
                                quoting=csv.QUOTE_NONE)
        for row in data:
            dataWriter.writerow(row)


if __name__ == '__main__':
    false_to_true()

score 1 · Answer 2 · answered Jan 05 '16 at 02:13

Open the input and output files, make a set out of the user-input names (terminated by a blank line), then create a generator for strings of the proper format that check for membership in the user-input names, then write these lines to the output file:

with open('names.txt') as f, open('result.txt', 'w') as out:
    names = {name for name in iter(input, '')}
    f = ('{}/{}/{}'.format(a,b,'True\n' if a in names else c) for a,b,c in (line.split('/') for line in f))
    output.writelines(f)

Kenly · Answer 3 · 2016-01-05T09:10:33.157

0

Ask for name and iterate throw your lines to check for username, like this:

def false_to_true():
    name = input("Input name: ")
    file=open("users.txt","r")
    lines = file.readlines()
    file.close()

    users = open("users.txt", "w")
    for line in lines:
    username, lel, type = line.split("/")
    if name == username:
        type = 'True\n'# \n for new line type ends with '\n'
    users.write("/".join([username, lel, type]))
    users.close()
false_to_true()

edited Jan 05 '16 at 09:10

answered Jan 04 '16 at 22:10

Kenly

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Your code delte all line in file and input last line of code in file? – Heimerdinger Jan 04 '16 at 22:33
i dont have #in file its only for a comment @Zetys – Heimerdinger Jan 04 '16 at 22:39

score 0 · Answer 4 · edited May 23 '17 at 11:45

To modify a text file inplace, you could use fileinput module:

#!/usr/bin/env python3
import fileinput

username = input('Enter username: ').strip()
with fileinput.FileInput("users.txt", inplace=True, backup='.bak') as file:
    for line in file:
        if line.startswith(username + "/"):            
            line = line.replace("/False", "/True") 
        print(line, end='')

See How to search and replace text in a file using Python?

Change text in file with Python

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