So I understand the logic but don't know how to get it to do what I want. I feel it's super simple but... I need it to record the last valid answer and store it into I but it returns the second to last value since the while loop doesn't iterate again. Relevant code and pictures are attached. Thank you all for any help.

INVALID_CHARACTERS = r"!#$%&'()* ,-.:;<=>?@[]^_`{|}~\/"   '"'
INVALID_NUMBERS = "1234567890"
INVALID_LETTERS = "abcdefghijklmnopqrstuvwxyz"

def letter_validity_check(i, msg):
    """Function checks entered answers against a list of invalid characters and invalid numbers"""

    while len(i) == 0 or any(c in INVALID_CHARACTERS for c in i) or any(c in INVALID_NUMBERS for c in i):
        i = input("First name can not be blank, contain special characters, or numbers. Try again. \n"   msg)

    while len(i) != 0 and any(c not in INVALID_CHARACTERS for c in i) and any(c not in INVALID_NUMBERS for c in i) and any(c in INVALID_LETTERS for c in i):
        print (i)
        return i

while len(FIRST_NAME) == 0:
    MESSAGE =  "What is your first name?: "
    FIRST_NAME = input(MESSAGE)
    letter_validity_check(FIRST_NAME, MESSAGE)
    print(FIRST_NAME)
    exit_checker(FIRST_NAME)

While loop and the logic

CodePudding user response：

You have a few issues here:

• syntax errors mixing i and I
• not saving the corrected name to FIRST_NAME
• unnecessary 2nd while loop in letter_validity_check

Here's a working solution that corrects these issues:

INVALID_CHARACTERS = r"!#$%&'()* ,-.:;<=>?@[]^_`{|}~\/"   '"'
INVALID_NUMBERS = "1234567890"
INVALID_LETTERS = "abcdefghijklmnopqrstuvwxyz"


def letter_validity_check(name, msg):
    """Function checks entered answers against a list of invalid characters and invalid numbers"""

    while (
        len(name) == 0
        or any(c in INVALID_CHARACTERS for c in name)
        or any(c in INVALID_NUMBERS for c in name)
    ):
        name = input(
            "First name can not be blank, contain special characters, or numbers. Try again. \n"
              msg
        )

    return name

    
FIRST_NAME = ""

while len(FIRST_NAME) == 0:
    MESSAGE = "What is your first name?: "
    FIRST_NAME = input(MESSAGE)
    FIRST_NAME = letter_validity_check(FIRST_NAME, MESSAGE)

print("Your first name is", FIRST_NAME)

A simpler version might be:

MESSAGE = "What is your first name? "
first_name = input(MESSAGE)

while not first_name.isalpha():
    print("First names may only contain alphabetic characters. Please try again.")
    first_name = input(MESSAGE)

print("Your first name is", first_name)