[BUG] Can't write Parquet file containing Decimal/Fixed Point column(s)

[randerzander]

Using the latest rapidsai-nightly conda package ('0.19.0a+248.g5d7767ec2f'):

import cudf
from cudf.core.dtypes import Decimal64Dtype

df = cudf.DataFrame()
df['id'] = [0, 1, 2]
df['val'] = [0.00, 0.01, 0.02]

df['dec_val'] = df['val'].astype(Decimal64Dtype(7,2))
df.to_parquet('test.parquet')

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-5-904034a55c73> in <module>
----> 1 df.to_parquet('test.parquet')

/conda/lib/python3.8/site-packages/cudf/core/dataframe.py in to_parquet(self, path, *args, **kwargs)
   7319         from cudf.io import parquet as pq
   7320 
-> 7321         return pq.to_parquet(self, path, *args, **kwargs)
   7322 
   7323     @ioutils.doc_to_feather()

/conda/lib/python3.8/site-packages/cudf/io/parquet.py in to_parquet(df, path, engine, compression, index, partition_cols, partition_file_name, statistics, metadata_file_path, int96_timestamps, *args, **kwargs)
    320                 )
    321         else:
--> 322             write_parquet_res = libparquet.write_parquet(
    323                 df,
    324                 path=path_or_buf,

cudf/_lib/parquet.pyx in cudf._lib.parquet.write_parquet()

cudf/_lib/parquet.pyx in cudf._lib.parquet.write_parquet()

cudf/_lib/utils.pyx in cudf._lib.utils.generate_pandas_metadata()

cudf/_lib/utils.pyx in cudf._lib.utils.generate_pandas_metadata()

/conda/lib/python3.8/site-packages/cudf/utils/dtypes.py in np_to_pa_dtype(dtype)
    123         # default fallback unit is ns
    124         return pa.duration("ns")
--> 125     return _np_pa_dtypes[np.dtype(dtype).type]
    126 
    127 

TypeError: Cannot interpret 'Decimal64Dtype(precision=7, scale=2)' as a data type