human
Complete this python program:
def choice(argument, values):
assistant
#Here is the Python program you requested.

    """Directive option utility function, supplied to enable options whose
    argument must be a member of a finite set of possible values (must be
    lower case).  A custom conversion function must be written to use it.  For
    example::
    from docutils.parsers.rst import directives
    def yesno(argument):
    return directives.choice(argument, (\yes\, \no\))
    Raise ``ValueError`` if no argument is found or if the argument\s value is
    not valid (not an entry in the supplied list).
    """
    try:
        value = argument.lower().strip()
    except AttributeError:
        raise ValueError(('must    supply    an    argument;    choose    from    %s' % format_values(values)))
    if (value in values):
        return value
    else:
        raise ValueError(('"%s"    unknown;    choose    from    %s' % (argument, format_values(values))))