Dask .to_parquet() errors when saving lists of integers (object types) with convert-string: False


The Related section helped me find a solution.

In case somebody struggles, this one works just fine:

import dask
import dask.dataframe as dd
import pandas as pd
dask.config.set({"dataframe.convert-string": False})

import pandas as pd
a = pd.DataFrame({"int_array_column1":[[1,2,3]],"int_array_column2":[[1,2,3]]})
ddf = dd.from_pandas(a,npartitions=1)

ddf_dd = ddf.to_parquet("testdd.parquet", schema={
    "int_array_column1": pa.list_(pa.int64()),
    "int_array_column2": pa.list_(pa.int64()),

Please feel free to close the thread, apologies for the mess, hopefully somebody can use this.

1 Like