Repeating until done

Question

So Ive got this code and I want to make it repeat itself until the user makes his username not start with a symbol or number.

  name=name.capitalize()
    print(name)
    surname= input("surname")
    surname=surname.capitalize()
    print(surname)
    password= input("password")
    username= input("username")
    first_char = username[0]
    if first_char.isalpha():
        print('done')
    else: print('username must start with a letter')

Answer 1

If you are using python 3.8, you can use the := operator for a nice way to write this:

while not (username := input("username: "))[0].isalpha():
    print('username must start with a letter')
# do stuff

Otherwise your choices are going to be:

(a) Repeat a line of code

username = input("username: ")
while not username[0].isalpha():
    print('username must start with a letter')
    username = input("username: ")
# do stuff

or (b) Use an infinite look with a break:

while True:
    username = input("username: ")
    if username[0].isalpha():
        break
    print('username must start with a letter')
# do stuff