# use one or more Standard Library modules
from secrets import choice
import string


def gen_key(parts: int = 4, chars_per_part: int = 8) -> str:
    """
    Generate and return a random license key containing
    upper case characters and digits.

    Example with default "parts" and "chars_per_part"
    being 4 and 8: KI80OMZ7-5OGYC1AC-735LDPT1-4L11XU1U

    If parts = 3 and chars_per_part = 4 a random license
    key would look like this: 54N8-I70K-2JZ7
    """

    key = ""
    for _ in range(parts):
        part = ""
        for _ in range(chars_per_part):
            part = part + choice(string.ascii_uppercase + string.digits)
        key = key + part + '-'
    
    # We don't want that final trailing dash.
    key = key[:-1]
    return key