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[netCDF #BSJ-787826]: NetCDF4 Python Error: attribute has unsupported datatype

It is probably best if you repost this as an issue
at the netcdf4-python gihub.
https://github.com/Unidata/netcdf4-python

> 
> I have an issue using the NetCDF4 python library, and I am hoping you guys 
> can help me with it. I am trying to read the variable attributes from the 
> following file: 
> https://oco2.gesdisc.eosdis.nasa.gov/data/s4pa/OCO2_DATA/OCO2_L2_Lite_FP.8r/2018/oco2_LtCO2_180117_B8100r_180221182228s.nc4
> 
> As an example, I am trying to read the attributes for the variable 
> vertex_longitude. (It fails for the rest, as well.) When I use the latest 
> netCDF4 python in conda, I get:
> 
> >>> print dataset.variables['vertex_longitude']
> Traceback (most recent call last):
> File "<stdin>", line 1, in <module>
> File "netCDF4.pyx", line 2302, in netCDF4.Variable.__str__ (netCDF4.c:25699)
> File "netCDF4.pyx", line 2307, in netCDF4.Variable.__unicode__ 
> (netCDF4.c:25941)
> File "netCDF4.pyx", line 2426, in netCDF4.Variable.getncattr (netCDF4.c:27513)
> File "netCDF4.pyx", line 934, in netCDF4._get_att (netCDF4.c:12165)
> KeyError: 'attribute units has unsupported datatype
> 
> 
> This is surprising given that when I use the ncdump in conda, I see the 
> attributes fine:
> 
> >/opt/anaconda/bin/ncdump -h copy.nc4 | grep vertex_longitude
> float vertex_longitude(sounding_id, vertices) ;
> string vertex_longitude:units = "degrees_east" ;
> string vertex_longitude:long_name = "vertex_longitude" ;
> vertex_longitude:missing_value = -999999.f ;
> string vertex_longitude:comment = "corner longitudes of the measurement FOV" ;
> 
> 
> When I h5dump this variable, I see:
> 
> /opt/anaconda/bin/h5dump -A -d /vertex_longitude 
> oco2_LtCO2_180117_B8100r_180221182228s.nc4
> HDF5 "oco2_LtCO2_180117_B8100r_180221182228s.nc4" {
> DATASET "/vertex_longitude" {
> DATATYPE  H5T_IEEE_F32LE
> DATASPACE  SIMPLE { ( 193218, 4 ) / ( 193218, 4 ) }
> ATTRIBUTE "DIMENSION_LIST" {
> DATATYPE  H5T_VLEN { H5T_REFERENCE { H5T_STD_REF_OBJECT }}
> DATASPACE  SIMPLE { ( 2 ) / ( 2 ) }
> DATA {
> (0): (DATASET 7216 /sounding_id ), (DATASET 8414 /vertices )
> }
> }
> ATTRIBUTE "comment" {
> DATATYPE  H5T_STRING {
> STRSIZE H5T_VARIABLE;
> STRPAD H5T_STR_NULLTERM;
> CSET H5T_CSET_UTF8;
> CTYPE H5T_C_S1;
> }
> DATASPACE  SIMPLE { ( 1 ) / ( 1 ) }
> DATA {
> (0): "corner longitudes of the measurement FOV"
> }
> }
> ATTRIBUTE "long_name" {
> DATATYPE  H5T_STRING {
> STRSIZE H5T_VARIABLE;
> STRPAD H5T_STR_NULLTERM;
> CSET H5T_CSET_UTF8;
> CTYPE H5T_C_S1;
> }
> DATASPACE  SIMPLE { ( 1 ) / ( 1 ) }
> DATA {
> (0): "vertex_longitude"
> }
> }
> ATTRIBUTE "missing_value" {
> DATATYPE  H5T_IEEE_F32LE
> DATASPACE  SIMPLE { ( 1 ) / ( 1 ) }
> DATA {
> (0): -999999
> }
> }
> ATTRIBUTE "units" {
> DATATYPE  H5T_STRING {
> STRSIZE H5T_VARIABLE;
> STRPAD H5T_STR_NULLTERM;
> CSET H5T_CSET_UTF8;
> CTYPE H5T_C_S1;
> }
> DATASPACE  SIMPLE { ( 1 ) / ( 1 ) }
> DATA {
> (0): "degrees_east"
> }
> }
> }
> }
> 
> Could you tell me a way that I can get the attributes form this variable in 
> python? Is there a way to directly access the methods like nc_inq_att and 
> whatnot through the python library?
> 
> Thanks,
> Paul
> 
> Paul Huwe, Ph.D.
> Senior Scientific Software Developer
> 
> GES DISC Code 610.2
> BLDG 32, S131-10
> Greenbelt, MD 20771
> (301) 614-5165
> address@hidden<mailto:address@hidden>
> 
> 
> 

=Dennis Heimbigner
  Unidata


Ticket Details
===================
Ticket ID: BSJ-787826
Department: Support netCDF
Priority: Normal
Status: Open
===================
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