def format_float(arg):
    """Formats a float value to be as short as possible.

    Trims extraneous trailing zeros and period to give API
    args the best possible chance of fitting within 2000 char
    URL length restrictions.

    For example:

    format_float(40) -> "40"
    format_float(40.0) -> "40"
    format_float(40.1) -> "40.1"
    format_float(40.001) -> "40.001"
    format_float(40.0010) -> "40.001"

    :param arg: The lat or lng float.
    :type arg: float

    :rtype: string
    """
    return ('%f' % float(arg)).rstrip('0').rstrip('.')
