Method write

qlib/data/storage/storage.py:299–352

Write data_array to FeatureStorage starting from index. Notes ------ If index is None, append data_array to feature. If len(data_array) == 0; return If (index - self.end_index) >= 1, self[end_index+1: index] will be filled with np.nan E

(self, data_array: Union[List, np.ndarray, Tuple], index: int = None)

        raise NotImplementedError("Subclass of FeatureStorage must implement `clear` method")

    def write(self, data_array: Union[List, np.ndarray, Tuple], index: int = None):
        """Write data_array to FeatureStorage starting from index.

        Notes
        ------
            If index is None, append data_array to feature.

            If len(data_array) == 0; return

            If (index - self.end_index) >= 1, self[end_index+1: index] will be filled with np.nan

        Examples
        ---------
            .. code-block::

                feature:
                    3   4
                    4   5
                    5   6


            >>> self.write([6, 7], index=6)

                feature:
                    3   4
                    4   5
                    5   6
                    6   6
                    7   7

            >>> self.write([8], index=9)

                feature:
                    3   4
                    4   5
                    5   6
                    6   6
                    7   7
                    8   np.nan
                    9   8

            >>> self.write([1, np.nan], index=3)

                feature:
                    3   1
                    4   np.nan
                    5   6
                    6   6
                    7   7
                    8   np.nan
                    9   8

        """
        raise NotImplementedError("Subclass of FeatureStorage must implement `write` method")

    def rebase(self, start_index: int = None, end_index: int = None):
        """Rebase the start_index and end_index of the FeatureStorage.