def query(text):
    return input(f"{text} \n> ")


def query_int(text):
    try:
        ans = query(text)
        return int(ans)
    except ValueError:
        print("Please enter a valid number!")
        return query_int(text)


def query_yes_no(question, default="no"):
    """Ask a yes/no question via raw_input() and return their answer.

    https://stackoverflow.com/questions/3041986/apt-command-line-interface-like-yes-no-input

    "question" is a string that is presented to the user.
    "default" is the presumed answer if the user just hits <Enter>.
            It must be "yes" (the default), "no" or None (meaning
            an answer is required of the user).

    The "answer" return value is True for "yes" or False for "no".
    """
    valid = {"yes": True, "y": True, "ye": True, "no": False, "n": False}
    if default is None:
        prompt = " [y/n] "
    elif default == "yes":
        prompt = " [Y/n] "
    elif default == "no":
        prompt = " [y/N] "
    else:
        raise ValueError("invalid default answer: '%s'" % default)

    while True:
        choice = query(question + prompt).lower()
        if default is not None and choice == "":
            return valid[default]
        elif choice in valid:
            return valid[choice]
        else:
            print("Please respond with 'yes' or 'no' (or 'y' or 'n').")