README.md

ecmwfspec

This is work in progress! This unofficial repository aims to provide an fsspec driver for the ECMWF File Storage System.

Pull requests (also for additional protocols like MARS and FDB) are welcomed!

import fsspec

with fsspec.open("ec:/<user>/path/to/file", "r") as f:
    print(f.read())

Loading datasets

import fsspec
import xarray as xr

url = fsspec.open("ec:/arch/project/file.grib").open()
ds = xr.open_dataset(url, engine='cfgrib')  # does not work until https://github.com/ecmwf/cfgrib/issues/326 is solved

Usage in connection with gribscan

This is just an example what ecmwfspec can be used for.

import gribscan
import json
import xarray as xr

file_to_scan = "ec:///path/to/some/grib/file/forecast+0038.grib2"
index_file = "index.json"
reference_file = "reference.json"

gribscan.write_index(gribfile=file_to_scan, idxfile=index_file)  # required currently patch https://github.com/gribscan/gribscan/commit/7a5e595759f48e3118964091358f1b2e9eb32b37 to work with fsspec paths
magician = gribscan.magician.HarmonieMagician()  # use magician fitting the grib file
refs = gribscan.grib_magic(
                        filenames=[index_file],
                        magician=magician,
                        global_prefix="",
                    )


with open(reference_file, "w") as outfile:
    json.dump(refs["heightAboveGround"], outfile)
ds = xr.open_zarr(f"reference::{reference_file}")
ds.u.max()  # with the help of ecmwfspec the data is now fetched if it is not locally cached