html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,performed_via_github_app,issue
https://github.com/pydata/xarray/issues/2822#issuecomment-477653931,https://api.github.com/repos/pydata/xarray/issues/2822,477653931,MDEyOklzc3VlQ29tbWVudDQ3NzY1MzkzMQ==,5186647,2019-03-28T15:48:04Z,2019-03-28T15:48:04Z,NONE,"Interesting! I wonder why using the netCDF4 python interface works fine with this scenario.  It must not be using the nccopy code.

I will see if I can test a newer netcdf library.  This is definitely an edge case, but thanks for providing a workaround!

The netCDF file is an excerpt from a hydrology water modeling input file.  Definitely a bit of legacy workflows and files involved.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,422903285
https://github.com/pydata/xarray/issues/2822#issuecomment-475487497,https://api.github.com/repos/pydata/xarray/issues/2822,475487497,MDEyOklzc3VlQ29tbWVudDQ3NTQ4NzQ5Nw==,1217238,2019-03-22T04:08:32Z,2019-03-22T04:08:32Z,MEMBER,"I can reproduce this with libnetcdf 4.6.2.

It looks like this problem is associated with having a `_NCProperties` attribute on a netCDF3 file:
```
>>> netCDF4.Dataset('some_netcdf_classic_file_simple.nc')
<class 'netCDF4._netCDF4.Dataset'>
root group (NETCDF3_CLASSIC data model, file format NETCDF3):
    _NCProperties: version=1|netcdflibversion=4.6.1|hdf5libversion=1.8.20
    Conventions: CF-1.5
    featureType: timeSeries
    NCO: netCDF Operators version 4.7.5 (Homepage = http://nco.sf.net, Code = http://github.com/nco/nco)
    nco_openmp_thread_number: 1
    dimensions(sizes): feature_id(1)
    variables(dimensions): >i4 Q_TYPE(feature_id), >f4 lat(feature_id), >f4 lon(feature_id)
    groups:
```

This appears to be fixed in libnetcdf 4.6.3 (https://github.com/Unidata/netcdf-c/issues/803), if you can upgrade to that version.

In the meantime, you can manually delete the `_NCProperties` attribute, e.g., `del data.attrs['_NCProperties']`

Out of curiosity, where did this netCDF file come from?","{""total_count"": 1, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 1, ""rocket"": 0, ""eyes"": 0}",,422903285
https://github.com/pydata/xarray/issues/2822#issuecomment-474907748,https://api.github.com/repos/pydata/xarray/issues/2822,474907748,MDEyOklzc3VlQ29tbWVudDQ3NDkwNzc0OA==,5186647,2019-03-20T16:13:43Z,2019-03-20T16:13:43Z,NONE,"
[minimal_example.tar.gz](https://github.com/pydata/xarray/files/2989093/minimal_example.tar.gz)
Here is a netcdf file and the minimal code to produce `AttributeError: NetCDF: String match to name in use`","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,422903285
https://github.com/pydata/xarray/issues/2822#issuecomment-474871120,https://api.github.com/repos/pydata/xarray/issues/2822,474871120,MDEyOklzc3VlQ29tbWVudDQ3NDg3MTEyMA==,1217238,2019-03-20T15:02:22Z,2019-03-20T15:02:22Z,MEMBER,"OK, in that case please provide a full example that I can run.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,422903285
https://github.com/pydata/xarray/issues/2822#issuecomment-474837398,https://api.github.com/repos/pydata/xarray/issues/2822,474837398,MDEyOklzc3VlQ29tbWVudDQ3NDgzNzM5OA==,5186647,2019-03-20T13:50:07Z,2019-03-20T13:50:07Z,NONE,"> ```
> with xr.open_dataset('some_netcdf_classic_file') as ds:
>     data = ds
>     # do something with data
>     data.to_netcdf('some_new_file', 'w')
> ```
> or
> 
> ```
> with xr.open_dataset('some_netcdf_classic_file') as ds:
>     data = ds.load()
> #do something with data
> data.to_netcdf('some_new_file', 'w')
> ```

I just tried both of these in a minimal example and I still get the same exception.  ","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,422903285
https://github.com/pydata/xarray/issues/2822#issuecomment-474641356,https://api.github.com/repos/pydata/xarray/issues/2822,474641356,MDEyOklzc3VlQ29tbWVudDQ3NDY0MTM1Ng==,1217238,2019-03-20T00:54:34Z,2019-03-20T00:54:43Z,MEMBER,"When you leave the `with` context, the original file is automatically closed.

But something like either of these should work:
```
with xr.open_dataset('some_netcdf_classic_file') as ds:
    data = ds
    # do something with data
    data.to_netcdf('some_new_file', 'w')
```
or
```
with xr.open_dataset('some_netcdf_classic_file') as ds:
    data = ds.load()
#do something with data
data.to_netcdf('some_new_file', 'w')
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,422903285