def to_representation(self, value): if self.min_timestamp is None and self.max_timestamp is None: return str(value) min_timestamp = self.min_timestamp or float('-inf') max_timestamp = self.max_timestamp or float('inf') ret = GeoLocationSeries('') for point in value: if point.timestamp < min_timestamp: continue elif point.timestamp > max_timestamp: continue else: ret.insert(point) return str(ret)