Code Jam 5 Qualifier

qualifier.py

import random
import string


def generate_password(
    password_length: int = 8,
    has_symbols: bool = False,
    has_uppercase: bool = False,
    ignored_chars: list = None,
    allowed_chars: list = None
) -> str:
    """Generates a random password.

    The password will be exactly `password_length` characters.
    If `has_symbols` is True, the password will contain at least one symbol, such as #, !, or @.
    If `has_uppercase` is True, the password will contain at least one upper case letter.
    If `ignored_chars` is passed, characters from the list won't be used.
    If `allowed_chars` is passed, only characters from the list will be used.

    Only one of the optional char list can be passed.
    """
    password = str()

    if ignored_chars and allowed_chars:
        # both lists to be passed at the same time
        raise UserWarning("You can't pass both char lists. Only one of them.")

    elif allowed_chars:
        # generate password using only `allowed_chars` symbols
        password = "".join([random.choice(allowed_chars) for _ in range(password_length)])

    else:
        # new list for the characters
        chars = list()

        # different lists for different categories of characters
        symbols = list(string.punctuation)
        uppercases = list(string.ascii_uppercase)
        other = list(string.ascii_lowercase + string.digits)

        if ignored_chars:
            # remove all ignonered characters from the list
            for c in ignored_chars:
                if c in symbols:
                    symbols.remove(c)
                elif c in uppercases:
                    uppercases.remove(c)
                else:
                    other.remove(c)

        if has_symbols:
            # generates random portion of symbols
            rand_int = random.randint(1, password_length-1)
            chars += random.choices(population=symbols, k=rand_int)
        if has_uppercase:
            # generates random portion of uppercase letters
            rand_int = random.randint(1, password_length - len(chars))
            chars += random.choices(population=uppercases, k=rand_int)

        if len(chars) != password_length:
            # if there are places left they must be filled with other symbols
            left = password_length-len(chars)
            chars += random.choices(population=other, k=left)

        # at the end shuffle the characters and contruct the string
        random.shuffle(chars)
        password = ''.join(chars)

    return password