dask.dataframe.groupby.SeriesGroupBy.nunique

SeriesGroupBy.nunique(split_every=None, split_out=1)

Return number of unique elements in the group.

This docstring was copied from pandas.core.groupby.generic.SeriesGroupBy.nunique.

Some inconsistencies with the Dask version may exist.

Returns:

Series

Number of unique values within each group.

Examples

>>> import pandas as pd
>>> import dask.dataframe as dd
>>> d = {'col1': [1, 2, 3, 4], 'col2': [5, 6, 7, 8]}
>>> df = pd.DataFrame(data=d)
>>> ddf = dd.from_pandas(df, 2)
>>> ddf.groupby(['col1']).col2.nunique().compute()