Source code for hed.tools.remodeling.operations.remove_columns_op

""" Remove columns from a columnar file. """
from hed.tools.remodeling.operations.base_op import BaseOp


[docs]class RemoveColumnsOp(BaseOp): """ Remove columns from a columnar file. Required remodeling parameters: - **column_names** (*list*): The names of the columns to be removed. - **ignore_missing** (*boolean*): If True, names in column_names that are not columns in df should be ignored. """ NAME = "remove_columns" PARAMS = { "type": "object", "properties": { "column_names": { "type": "array", "items": { "type": "string" }, "minItems": 1, "uniqueItems": True }, "ignore_missing": { "type": "boolean" } }, "required": [ "column_names", "ignore_missing" ], "additionalProperties": False }
[docs] def __init__(self, parameters): """ Constructor for remove columns operation. Parameters: parameters (dict): Dictionary with the parameter values for required and optional parameters. """ super().__init__(parameters) self.column_names = parameters['column_names'] ignore_missing = parameters['ignore_missing'] if ignore_missing: self.error_handling = 'ignore' else: self.error_handling = 'raise'
[docs] def do_op(self, dispatcher, df, name, sidecar=None): """ Remove indicated columns from a dataframe. Parameters: dispatcher (Dispatcher): Manages the operation I/O. df (DataFrame): The DataFrame to be remodeled. name (str): Unique identifier for the dataframe -- often the original file path. sidecar (Sidecar or file-like): Not needed for this operation. Returns: Dataframe: A new dataframe after processing. :raises KeyError: - If ignore_missing is False and a column not in the data is to be removed. """ df_new = df.copy() try: return df_new.drop(self.column_names, axis=1, errors=self.error_handling) except KeyError: raise KeyError("MissingColumnCannotBeRemoved", f"{name}: Ignore missing is False but a column in {str(self.column_names)} is " f"not in the data columns [{str(df_new.columns)}]")
[docs] @staticmethod def validate_input_data(parameters): """ Additional validation required of operation parameters not performed by JSON schema validator. """ return []