def _utf8(value):
    """Converts a string argument to a byte string.

    If the argument is already a byte string or None, it is returned unchanged.
    Otherwise it must be a unicode string and is encoded as utf8.
    """
    if isinstance(value, _UTF8_TYPES):
        return value
    if not isinstance(value, unicode_type):
        raise TypeError(
            "Expected bytes, unicode, or None; got %r" % type(value)
        )
    return value.encode("utf-8")
def _utf8 ( value ) : if isinstance ( value , _UTF8_TYPES ) : return value if not isinstance ( value , unicode_type ) : raise TypeError ( "Expected bytes, unicode, or None; got %r" % type ( value ) ) return value . encode ( "utf-8" )
Converts a string argument to a byte string.

    If the argument is already a byte string or None, it is returned unchanged.
    Otherwise it must be a unicode string and is encoded as utf8.