def abbreviate_string(s, limit=60):
    """Returns first x characters of a string.

    Args:
        s (str): String to be shortened
        limit (int): Maximum length of string. Default value is 60.

    Returns:
        str: Shortened string.

    Raises:
        TypeError: If input is not a string.
    """
    if not isinstance(s, str):
        raise TypeError("Input is not a string")
    return s[:limit]