Question

This task is solved in Python 3.

Develop a program that can change the phone number of a person in phone.txt (hint: the easiest thing is probably to make a new version of the file, and then delete the old one before the new is renamed to phone.txt)

Name: John

Old phone number: 99776612

New number: 99889999

>>>

phone.txt	Replaced by ------>	phone.txt
Mary 98654321 June 99776655 Chris 99112233 Viv 98554455 John 99776612 Joe 97888776 Rick 99455443 Susan 98122134 Jill 99655732 Bob 98787896		Mary 98654321 June 99776655 Chris 99112233 Viv 98554455 John 99889999 Joe 97888776 Rick 99455443 Susan 98122134 Jill 99655732 Bob 98787896

Answer 1

# Python Code

# read phone.txt
try:
    file = open("phone.txt", 'r')
    phone_book = []
    for i in file:
        line = i.rstrip().split(" ")
        phone_book.append(line)
    # close the file
    file.close()
    # delete file
    del(file)
    name = input("Name: ")
    old_phone_number =input("Old phone number: ")
    new_number = input("New Number: ")
    # open file writing mode
    file1 = open("phone.txt", 'w')
    # search number in the list
    for i in phone_book:
        if i[1] == old_phone_number:
            i[1] = new_number
        # now write the complete data to phone.txt
        file1.write(i[0]+" "+i[1]+"\n")
    # close the file
    file1.close()


except FileNotFoundError:
    print("File not found")

# file

# Output

//If you need any help regarding this solution... please leave a comment. thanks