Thanks, Arthur, this helps.  The complete code example is:

filename = 'gs://' + files[0]
gs = gcsfs.GCSFileSystem()
f = gs.open(filename)
pqf = pq.ParquetFile(f)
pqf.metadata


On Thu, Dec 23, 2021 at 1:48 AM Arthur Andres <[email protected]>
wrote:

> Hi Cindy,
>
> In your case you'd have to pass a GCS file instance to the ParquetFile
> constructor. Something like this:
>
> source = fs.open_input_file(filename)
> parquet_file = pq.ParquetFile(source)
>
> You can see how read_table does this in the source code:
> https://github.com/apache/arrow/blob/16c442a03e2cf9c7748f0fa67b6694dbeb287fad/python/pyarrow/parquet.py#L1977
>
> I hope this helps.
>
>
>
> On Thu, 23 Dec 2021 at 05:17, Cindy McMullen <[email protected]>
> wrote:
>
>> Hi -
>>
>> I need to drop down to the ParquetFile API so I can have better control
>> over batch size for reading huge Parquet files.  The filename is:
>>
>>
>> *gs://graph_infra_steel_thread/output_pq/parquet/usersims/output-20211202-220329-20211202-220329-00-0012.parquet.snappy*
>>
>> This invocation fails:
>> *pqf = pq.ParquetFile(filename)*
>> "FileNotFoundError: [Errno 2] Failed to open local file
>> 'gs://graph_infra_steel_thread/output_pq/parquet/usersims/output-20211202-220329-20211202-220329-00-0012.parquet.snappy'.
>> Detail: [errno 2] No such file or directory"
>>
>> While this API, using the same, succeeds because I can specify 'gs'
>> filesystem.
>> *table = pq.read_table(filename, filesystem=gs,
>> use_legacy_dataset=False) *
>>
>> I don't see a way to specify 'filesystem' on the ParquetFile API
>> <https://arrow.apache.org/docs/python/generated/pyarrow.parquet.ParquetFile.html#pyarrow.parquet.ParquetFile>.
>> Is there any way to read a GCS file using ParquetFile?
>>
>> If not, can you show me the code for reading batches using pq.read_table
>> or one of the other Arrow Parquet APIs
>> <https://arrow.apache.org/docs/python/api/formats.html#parquet-files>?
>>
>> Thanks -
>>
>> -- Cindy
>>
>

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