Hi Alenka,
Here is the code snippet that loads a single Parquet file. I can also confirm
that it appears to be with the function call “fs.isfile” on the root directory…
calling this function myself returns False, as I would expect it should:
fs.isfile("global-radiosondes/hires-sonde”)
fs = gcsfs.GCSFileSystem(token="anon")
partitioning = ds.HivePartitioning(
pyarrow.schema([
pyarrow.field('year', pyarrow.int32()),
pyarrow.field('month', pyarrow.int32()),
pyarrow.field('day', pyarrow.int32()),
pyarrow.field('hour', pyarrow.int32()),
pyarrow.field('WMO', pyarrow.string())
])
)
schema = pyarrow.schema([
pyarrow.field('lon', pyarrow.float32()),
pyarrow.field('lat', pyarrow.float32()),
pyarrow.field('pres', pyarrow.float32()),
pyarrow.field('hght', pyarrow.float32()),
pyarrow.field('gpht', pyarrow.float32()),
pyarrow.field('tmpc', pyarrow.float32()),
pyarrow.field('dwpc', pyarrow.float32()),
pyarrow.field('relh', pyarrow.float32()),
pyarrow.field('uwin', pyarrow.float32()),
pyarrow.field('vwin', pyarrow.float32()),
pyarrow.field('wspd', pyarrow.float32()),
pyarrow.field('wdir', pyarrow.float32()),
pyarrow.field('year', pyarrow.int32()),
pyarrow.field('month', pyarrow.int32()),
pyarrow.field('day', pyarrow.int32()),
pyarrow.field('hour', pyarrow.int32()),
pyarrow.field('WMO', pyarrow.string())
])
data =
ds.dataset("global-radiosondes/hires-sonde/year=2016/month=5/day=24/hour=19/WMO=72451",
filesystem=fs, format="parquet", \
schema=schema, partitioning=partitioning)
batches = data.to_batches(columns=["pres", "gpht", "hght", "tmpc", "wspd",
"wdir"], \
use_threads=True)
batches = list(batches)
print(batches[0].to_pandas().head())
Kelton.
> On Feb 21, 2022, at 3:07 AM, Alenka Frim <ale...@voltrondata.com> wrote:
>
> Hi Kelton,
>
> I can reproduce the same error if I try to load all the data with data =
> ds.dataset("global-radiosondes/hires-sonde", filesystem=fs) or data =
> pq.ParquetDataset("global-radiosondes/hires-sonde", filesystem=fs,
> use_legacy_dataset=False).
>
> Could you share your code, where you read a specific parquet file?
>
> Best,
> Alenka
>
> On Mon, Feb 21, 2022 at 12:04 AM Kelton Halbert <kthalb...@wxbyte.com
> <mailto:kthalb...@wxbyte.com>> wrote:
> Hello,
>
> I’ve been learning and working with PyArrow recently for a project to store
> some atmospheric science data as part of a partitioned dataset, and recently
> the dataset class with the fsspec/gcsfs filesystem has started producing a
> new error. Unfortunately I cannot seem to track down what changed or if it’s
> an error on my end or not. I’m using PyArrow 7.0.0 and python 3.8.
>
> If I specify a specific parquet file, everything is fine - but if I give it
> any of the directory partitions, the same issue occurs. Any guidance here
> would be appreciated!
>
> The code:
> fs = gcsfs.GCSFileSystem(token="anon")
>
> partitioning = ds.HivePartitioning(
> pyarrow.schema([
> pyarrow.field('year', pyarrow.int32()),
> pyarrow.field('month', pyarrow.int32()),
> pyarrow.field('day', pyarrow.int32()),
> pyarrow.field('hour', pyarrow.int32()),
> pyarrow.field('WMO', pyarrow.string())
> ])
> )
>
> schema = pyarrow.schema([
> pyarrow.field('lon', pyarrow.float32()),
> pyarrow.field('lat', pyarrow.float32()),
> pyarrow.field('pres', pyarrow.float32()),
> pyarrow.field('hght', pyarrow.float32()),
> pyarrow.field('gpht', pyarrow.float32()),
> pyarrow.field('tmpc', pyarrow.float32()),
> pyarrow.field('dwpc', pyarrow.float32()),
> pyarrow.field('relh', pyarrow.float32()),
> pyarrow.field('uwin', pyarrow.float32()),
> pyarrow.field('vwin', pyarrow.float32()),
> pyarrow.field('wspd', pyarrow.float32()),
> pyarrow.field('wdir', pyarrow.float32()),
> pyarrow.field('year', pyarrow.int32()),
> pyarrow.field('month', pyarrow.int32()),
> pyarrow.field('day', pyarrow.int32()),
> pyarrow.field('hour', pyarrow.int32()),
> pyarrow.field('WMO', pyarrow.string())
> ])
>
> data = ds.dataset("global-radiosondes/hires-sonde", filesystem=fs,
> format="parquet", \
> partitioning=partitioning, schema=schema)
>
> subset = (ds.field("year") == 2016) & (ds.field("WMO") == "72451")
>
> batches = data.to_batches(columns=["pres", "gpht", "tmpc", "wspd", "wdir",
> "year", "month", "day", "hour"], \
> use_threads=True)
>
> batches = list(batches)
>
> The error:
> 391 from pyarrow import PythonFile
> 393 if not self.fs.isfile(path):
> --> 394 raise FileNotFoundError(path)
> 396 return PythonFile(self.fs.open(path, mode="rb"), mode="r")
>
> FileNotFoundError: global-radiosondes/hires-sonde/
>
