value_mapping

value_mapping ¤

ValueMapper ¤

ValueMapper(
    dataframe: DataFrame,
    mapping_file: str,
    map_column: str,
    mapping_key_column: str,
    mapping_value_column: str,
    file_type: str = "csv",
    sep: str = ",",
    encoding: str = "utf-8",
    time_column: str = "systime",
)

Bases: Base

A class to map values from specified columns of a DataFrame using a mapping table (CSV or JSON file), inheriting from the Base class.

Initializes ValueMapper and the base DataFrame from the Base class.

Parameters:

Name	Type	Description	Default
`dataframe`	`DataFrame`	The DataFrame to be processed and mapped.	required
`mapping_file`	`str`	The file path of the mapping table (CSV or JSON).	required
`map_column`	`str`	The name of the column in the DataFrame that needs to be mapped.	required
`mapping_key_column`	`str`	The column in the mapping table to match with values from the DataFrame.	required
`mapping_value_column`	`str`	The column in the mapping table containing the values to map to.	required
`file_type`	`str`	The type of the mapping file ('csv' or 'json'). Defaults to 'csv'.	`'csv'`
`sep`	`str`	The separator for CSV files. Defaults to ','.	`','`
`encoding`	`str`	The encoding to use for reading the file. Defaults to 'utf-8'.	`'utf-8'`
`time_column`	`str`	Timestamp column the base class sorts by (formerly `column_name`). Defaults to 'systime'.	`'systime'`

map_values ¤

map_values() -> pd.DataFrame

Maps values in the specified DataFrame column based on the mapping table.

Keys are compared as text, so a mapping file with string keys maps an integer code column (1, 1.0 and "1" all match). Codes the table does not contain keep their original value, with a :class:~ts_shape.errors.DataQualityWarning counting them. The other columns of the DataFrame are unchanged, whatever the mapping table's column names are.

Returns:

Type	Description
`DataFrame`	pd.DataFrame: A new DataFrame with the mapped values.

Raises:

Type	Description
`ColumnNotFoundError`	When `map_column` or a mapping-table column is missing.
`ValueError`	When the mapping table has duplicate keys, or the key and value columns of the mapping table are the same column.