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Wes McKinney commented on ARROW-1644: ------------------------------------- The work is pretty much all on the parquet-cpp side, so strictly an Arrow <-> Parquet nested encoding conversion problem in C++. We'll want to have unit tests in pyarrow to verify that we can faithfully round trip the data of course. I think Python will be useful for generating schemas and synthetic data sets to find edge cases > [Python] Read and write nested Parquet data with a mix of struct and list > nesting levels > ---------------------------------------------------------------------------------------- > > Key: ARROW-1644 > URL: https://issues.apache.org/jira/browse/ARROW-1644 > Project: Apache Arrow > Issue Type: New Feature > Components: Python > Affects Versions: 0.8.0 > Reporter: DB Tsai > > We have many nested parquet files generated from Apache Spark for ranking > problems, and we would like to load them in python for other programs to > consume. > The schema looks like > {code:java} > root > |-- profile_id: long (nullable = true) > |-- country_iso_code: string (nullable = true) > |-- items: array (nullable = false) > | |-- element: struct (containsNull = false) > | | |-- show_title_id: integer (nullable = true) > | | |-- duration: double (nullable = true) > {code} > And when I tried to load it with nightly build pyarrow on Oct 4, 2017, I got > the following error. > {code:python} > Python 3.6.2 |Anaconda, Inc.| (default, Sep 30 2017, 18:42:57) > [GCC 7.2.0] on linux > Type "help", "copyright", "credits" or "license" for more information. > >>> import numpy as np > >>> import pandas as pd > >>> import pyarrow as pa > >>> import pyarrow.parquet as pq > >>> table2 = pq.read_table('part-00000') > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > File "/home/dbt/miniconda3/lib/python3.6/site-packages/pyarrow/parquet.py", > line 823, in read_table > use_pandas_metadata=use_pandas_metadata) > File "/home/dbt/miniconda3/lib/python3.6/site-packages/pyarrow/parquet.py", > line 119, in read > nthreads=nthreads) > File "_parquet.pyx", line 466, in pyarrow._parquet.ParquetReader.read_all > File "error.pxi", line 85, in pyarrow.lib.check_status > pyarrow.lib.ArrowNotImplementedError: lists with structs are not supported. > {code} > I somehow get the impression that after > https://issues.apache.org/jira/browse/PARQUET-911 is merged, we should be > able to load the nested parquet in pyarrow. > Any insight about this? > Thanks. -- This message was sent by Atlassian JIRA (v6.4.14#64029)