def get_issue_number_from_card_data(card_data: dict) ->int:
    """
    Returns the issue number from the given card data

    Can be None if the card is a note or some other non-issue card

    Args:
        card_data: the card data returned by the GH API

    Returns:
        Issue number or None
    """
    content_url = card_data.get('content_url')
    if not content_url:
        return
    issue_number = content_url.rsplit('/', 1)[-1]
    return int(issue_number)
