Gets username from YAML file, password from keyring, otherwise prompt user via click

auth.py

try:
    config = yaml.load(open(CONFIGFILE).read())
except:
    config = None

if not config: config = {}

username = config.get('username', None)
password = keyring.get_password(PROGRAM, username) if username else None

@click.command()
@click.option('--username', '-u', type=str, default=username, required=not username)
@click.option('--password', '-p', type=str, hide_input=True, confirmation_prompt=True, default=password, prompt=not password)
def main(username, password):
    session = tidalapi.Session()
    session.login(username, password)

    if not session.check_login():
        click.echo("Invalid credentials.")
        raise SystemError