How can I select data from a dask dataframe by a list of indices?

Question

I want to select rows from a dask dataframe based on a list of indices. How can I do that?

Example: Let\'s say, I have the following dask dataframe. <

Answer 1

Edit: dask now supports loc on lists:

ddf_selected = ddf.loc[indices_i_want_to_select]

The following should still work, but is not necessary anymore:

import pandas as pd
import dask.dataframe as dd

#generate example dataframe
pdf = pd.DataFrame(dict(A = [1,2,3,4,5], B = [6,7,8,9,0]), index=['i1', 'i2', 'i3', 4, 5])
ddf = dd.from_pandas(pdf, npartitions = 2)

#list of indices I want to select
l = ['i1', 4, 5]

#generate new dask dataframe containing only the specified indices
ddf_selected = ddf.map_partitions(lambda x: x[x.index.isin(l)], meta = ddf.dtypes)