netCDF4 1.6.0 in colab doesn't support remote data reading via opendap

[ngam]

Describe the current behavior
Currently, the installed netCDF4 in colab cannot read remote data via opendap (see end of section here: https://unidata.github.io/netcdf4-python/#creatingopeningclosing-a-netcdf-file).

Describe the expected behavior
In the future, netCDf4 should be able to read remote data files like below. Alternatively, downgrading to netCDf4==1.5.8 from PyPI does the trick. Or from the same link above:

Remote OPeNDAP-hosted datasets can be accessed for reading over http if a URL is provided to the Dataset constructor instead of a filename. However, this requires that the netCDF library be built with OPenDAP support, via the --enable-dap configure option (added in version 4.0.1).

What web browser you are using
Safari.

Additional context
See code for a repro.

--

repro code:

BUG (current)

import netCDF4
print("current buggy version: ", netCDF4.__version__)
try:
    nc = netCDF4.Dataset(
        "https://psl.noaa.gov/thredds/dodsC/Datasets/" +
        "ncep.reanalysis2" +
        "/pressure/air.2020.nc"
    )
    print(nc)
except Exception as err:
    print(err)

current buggy version:  1.6.0
[Errno -68] NetCDF: I/O failure: b'https://psl.noaa.gov/thredds/dodsC/Datasets/ncep.reanalysis2/pressure/air.2020.nc'

FIX (wanted!)

!pip install netCDF4==1.5.8 -qqq
# restart kernel and try again with 1.5.8
import netCDF4
print("one good version from PyPI: ", netCDF4.__version__)
try:
    nc = netCDF4.Dataset(
        "https://psl.noaa.gov/thredds/dodsC/Datasets/" +
        "ncep.reanalysis2" +
        "/pressure/air.2020.nc"
    )
    print(nc)
except Exception as err:
    print(err)

one good version from PyPI:  1.5.8
<class 'netCDF4._netCDF4.Dataset'>
root group (NETCDF3_CLASSIC data model, file format DAP2):
    Conventions: CF-1.0
    title: 4x Daily NCEP/DOE Reanalysis 2
    comments: Data is from 
NCEP/DOE AMIP-II Reanalysis (Reanalysis-2)
(4x/day).  It consists of most variables interpolated to
pressure surfaces from model (sigma) surfaces.
    platform: Model
    source: NCEP/DOE AMIP-II Reanalysis (Reanalysis-2) Model
    institution: National Centers for Environmental Prediction
    dataset_title: NCEP-DOE AMIP-II Reanalysis
    References: https://www.psl.noaa.gov/data/gridded/data.ncep.reanalysis2.html
    source_url: http://www.cpc.ncep.noaa.gov/products/wesley/reanalysis2/
    history: created 2020/02 by NOAA/ESRL/PSD
Converted to chunked, deflated non-packed NetCDF4 2020/05
    DODS_EXTRA.Unlimited_Dimension: time
    dimensions(sizes): time(1464), lat(73), level(17), lon(144)
    variables(dimensions): float32 level(level), float32 lat(lat), float32 lon(lon), float64 time(time), float32 air(time, level, lat, lon)
    groups: 

[colaboratory-team]

Thanks for the report, they're tracking this on the netcdf4 side as well, Unidata/netcdf4-python#1179

We may pin to 1.5.8 until they push a new build

[ngam]

Great, thanks!

[Gui-FernandesBR]

Thanks for the report, they're tracking this on the netcdf4 side as well, Unidata/netcdf4-python#1179

We may pin to 1.5.8 until they push a new build

Hey, @colaboratory-team , it seems that the new netcdf4==1.6.4 version fixed the problem. Shall we give it a try in Colab?

Just saw it on the following comment: Unidata/netcdf4-python#1246 (comment)