code: def test_dataframe_assign_col():
      df = cudf.DataFrame(list(range(100)))
      pdf = pd.DataFrame(list(range(100)))
  
      ddf = dgd.from_cudf(df, npartitions=4)
      ddf["fold"] = 0
      ddf["fold"] = ddf["fold"].map_partitions(
          lambda cudf_df: cp.random.randint(0, 4, len(cudf_df))
      )
  
      pddf = dd.from_pandas(pdf, npartitions=4)
      pddf["fold"] = 0
      pddf["fold"] = pddf["fold"].map_partitions(
          lambda p_df: np.random.randint(0, 4, len(p_df))
      )
  
      dd.assert_eq(ddf[0], pddf[0])
      dd.assert_eq(len(ddf["fold"]), len(pddf["fold"]))
  
imports: import random
  import cupy
  import numpy
  import pandas
  import pytest
  from packaging import version
  import dask
  from dask import dataframe
  from dask.dataframe.core import make_meta, meta_nonempty
  from dask.utils import M
  import cudf
  import dask_cudf
label_desc: Use image node_id 41 for calling a global function with example usage: test_dataframe_assign_col() without return types