def validate_is_string_or_number(var):
    """
    Checks if the input is either a str, int or float.

    :param var: input
    :raises: TypeError if not
    :returns: True
    """
    valid_types = (str, int, float)
    if not isinstance(var, valid_types):
        raise TypeError("Input is not a string or a number:" + str(var))

    return True