dask_ml.preprocessing.BlockTransformer

class dask_ml.preprocessing.BlockTransformer(func: Callable[[...], Union[dask_ml._typing.ArrayLike, pandas.core.frame.DataFrame, dask.dataframe.core.DataFrame]], *, validate: bool = False, **kw_args: Any)

Construct a transformer from a an arbitrary callable

The BlockTransformer forwards the blocks of the X arguments to a user-defined callable and returns the result of this operation. This is useful for stateless operations, that can be performed on the cell or block level, such as taking the log of frequencies. In general the transformer is not suitable for e.g. standardization tasks as this requires information for a complete column.

Parameters
funccallable

The callable to use for the transformation.

validatebool, optional default=False

Indicate that the input X array should be checked before calling

func.

kw_argsdict, optional

Dictionary of additional keyword arguments to pass to func.

Examples

>>> import dask.datasets
>>> import pandas as pd
>>> from dask_ml.preprocessing import BlockTransformer
>>> df = dask.datasets.timeseries()
>>> df
... 
Dask DataFrame Structure:
                   id    name        x        y
npartitions=30
2000-01-01      int64  object  float64  float64
2000-01-02        ...     ...      ...      ...
...               ...     ...      ...      ...
2000-01-30        ...     ...      ...      ...
2000-01-31        ...     ...      ...      ...
Dask Name: make-timeseries, 30 tasks
>>> trn = BlockTransformer(pd.util.hash_pandas_object, index=False)
>>> trn.transform(df)
... 
Dask Series Structure:
npartitions=30
2000-01-01    uint64
2000-01-02       ...
            ...
2000-01-30       ...
2000-01-31       ...
dtype: uint64
Dask Name: hash_pandas_object, 60 tasks

Methods

fit_transform(X[, y])

Fit to data, then transform it.

get_params([deep])

Get parameters for this estimator.

set_params(**params)

Set the parameters of this estimator.

fit

transform

__init__(func: Callable[[...], Union[dask_ml._typing.ArrayLike, pandas.core.frame.DataFrame, dask.dataframe.core.DataFrame]], *, validate: bool = False, **kw_args: Any)