ddf.stainer.NullifyStainer

class ddf.stainer.NullifyStainer(deg, name='Nullify', row_idx=[], col_idx=[], new_val=None, new_type=False)

Stainer that convert various values to missing data / values that represent missing values.

__init__(deg, name='Nullify', row_idx=[], col_idx=[], new_val=None, new_type=False)

The constructor for NullifyStainer class.

Parameters

  • deg (float (0, 1]) – Determines the proportion of selected data that would be nullified

  • name (str, optional) – Name of stainer. Default is “Nullify”

  • row_idx (int list, optional) – Indices of rows which will be considered for transformation (depending on the degree). Default is empty list

  • col_idx (int list, optional) – Indices of columns which will be considered for transformation (depending on the degree). Default is empty list

  • new_val (any, optional) – Value that would replace the specific data. Defaults to None

  • new_type (boolean, optional) –

    Allows the new_val to be of a different type than the current column.

    Defaults to False (new_val must be same type as the column to be changed)

Raises

  • ValueError – Degree provided is not in the range of (0, 1]

  • TypeError – Only when new_type is set to False. Denotes column type is being changed via the addition of the new_val.

get_col_type()

Returns the column type that the stainer operates on.

Returns

Column type that the stainer operates on.

Return type

string

get_history()

Compiles history information for this stainer and returns it.

Returns

  • name (str) – Name of stainer.

  • msg (str) – Message for user.

  • time (float) – Time taken to execute the self.transform() method.

get_indices()

Returns the row indices and column indices.

Returns

  • row_idx (int list) – Row indices that the stainer operates on.

  • col_idx (int list) – Column indices that the stainer operates on.

transform(df, rng, row_idx=None, col_idx=None)

Applies staining on the given indices in the provided dataframe.

Parameters

  • df (pd.DataFrame) – Dataframe to be transformed.

  • rng (np.random.BitGenerator) – PCG64 pseudo-random number generator.

  • row_idx (int list, optional) – Row indices that the stainer will operate on.

  • col_idx (int list, optional) – Column indices that the stainer will operate on.

Returns

  • new_df (pd.DataFrame) – Modified dataframe.

  • row_map (empty dictionary) – This stainer does not produce any row mappings.

  • col_map (empty dictionary) – This stainer does not produce any column mappings.

update_history(message='', time=0)

Used by transform method to set attributes required to display history information

Parameters

  • message (str) – Mesasge to be shown to user about the transformation

  • time (float) – Time taken to perform the transform

Methods

__init__(deg[, name, row_idx, col_idx, …])

The constructor for NullifyStainer class.

get_col_type()

Returns the column type that the stainer operates on.

get_history()

Compiles history information for this stainer and returns it.

get_indices()

Returns the row indices and column indices.

transform(df, rng[, row_idx, col_idx])

Applies staining on the given indices in the provided dataframe.

update_history([message, time])

Used by transform method to set attributes required to display history information