def _CheckFilter(self, filter, values):
    """Type check a filter string and list of values.

    Raises BadFilterError if the filter string is empty, not a string, or
    invalid. Raises BadValueError if the value type is not supported.

    Args:
      filter: String containing the filter text.
      values: List of associated filter values.

    Returns:
      re.MatchObject (never None) that matches the 'filter'. Group 1 is the
      property name, group 3 is the operator. (Group 2 is unused.)
    """
    try:
      match = Query.FILTER_REGEX.match(filter)
      if not match:
        raise datastore_errors.BadFilterError(
          'Could not parse filter string: %s' % str(filter))
    except __HOLE__:
      raise datastore_errors.BadFilterError(
        'Could not parse filter string: %s' % str(filter))

    property = match.group(1)
    operator = match.group(3)
    if operator is None:
      operator = '='

    if isinstance(values, tuple):
      values = list(values)
    elif not isinstance(values, list):
      values = [values]
    if isinstance(values[0], datastore_types._RAW_PROPERTY_TYPES):
      raise datastore_errors.BadValueError(
        'Filtering on %s properties is not supported.' % typename(values[0]))

    if (operator in self.INEQUALITY_OPERATORS and
        property != datastore_types._UNAPPLIED_LOG_TIMESTAMP_SPECIAL_PROPERTY):
      if self.__inequality_prop and property != self.__inequality_prop:
        raise datastore_errors.BadFilterError(
            'Only one property per query may have inequality filters (%s).' %
            ', '.join(self.INEQUALITY_OPERATORS))
      elif len(self.__orderings) >= 1 and self.__orderings[0][0] != property:
        raise datastore_errors.BadFilterError(
            'Inequality operators (%s) must be on the same property as the '
            'first sort order, if any sort orders are supplied' %
            ', '.join(self.INEQUALITY_OPERATORS))

    if (self.__kind is None and
        property != datastore_types.KEY_SPECIAL_PROPERTY and
        property != datastore_types._UNAPPLIED_LOG_TIMESTAMP_SPECIAL_PROPERTY):
      raise datastore_errors.BadFilterError(
          'Only %s filters are allowed on kindless queries.' %
          datastore_types.KEY_SPECIAL_PROPERTY)

    if property == datastore_types._UNAPPLIED_LOG_TIMESTAMP_SPECIAL_PROPERTY:
      if self.__kind:
        raise datastore_errors.BadFilterError(
            'Only kindless queries can have %s filters.' %
            datastore_types._UNAPPLIED_LOG_TIMESTAMP_SPECIAL_PROPERTY)
      if not operator in self.UPPERBOUND_INEQUALITY_OPERATORS:
        raise datastore_errors.BadFilterError(
            'Only %s operators are supported with %s filters.' % (
            self.UPPERBOUND_INEQUALITY_OPERATORS,
            datastore_types._UNAPPLIED_LOG_TIMESTAMP_SPECIAL_PROPERTY))

    if property in datastore_types._SPECIAL_PROPERTIES:




      if property == datastore_types.KEY_SPECIAL_PROPERTY:
        for value in values:
          if not isinstance(value, Key):
            raise datastore_errors.BadFilterError(
              '%s filter value must be a Key; received %s (a %s)' %
              (datastore_types.KEY_SPECIAL_PROPERTY, value, typename(value)))

    return match
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/api/datastore.py/Query._CheckFilter