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/3034#issuecomment-517919790,https://api.github.com/repos/pydata/xarray/issues/3034,517919790,MDEyOklzc3VlQ29tbWVudDUxNzkxOTc5MA==,32473508,2019-08-03T12:08:05Z,2019-08-03T12:08:05Z,CONTRIBUTOR,@jfpiolle Thank you very much for the clarification,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,457874038
https://github.com/pydata/xarray/issues/3034#issuecomment-516776060,https://api.github.com/repos/pydata/xarray/issues/3034,516776060,MDEyOklzc3VlQ29tbWVudDUxNjc3NjA2MA==,11731042,2019-07-31T09:38:02Z,2019-07-31T09:38:02Z,NONE,"@HasanAhmadQ7 You can have attributes of type list. See for instance this code:

```
from netCDF4 import Dataset
import numpy

f = Dataset(""example.nc"",""w"")
x = f.createDimension(""x"",3)
vlvar = f.createVariable(""test_var"", numpy.int32, (""x""))

# here create an attribute as a list
vlvar.test_attr = [""string a"", ""string b""]

vlvar[:] = numpy.arange(3)
f.close()
```

Having files with different values for the `test_attr` attribute will cause `open_mfdataset` to fail.

thanks for addressing this!","{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,457874038
https://github.com/pydata/xarray/issues/3034#issuecomment-515654610,https://api.github.com/repos/pydata/xarray/issues/3034,515654610,MDEyOklzc3VlQ29tbWVudDUxNTY1NDYxMA==,32473508,2019-07-27T05:41:59Z,2019-07-27T08:15:07Z,CONTRIBUTOR,"@jfpiolle Would you please share the files, or the code generating them?

As far as I understand we cannot have an attribute of type list. The closest thing I can think of is a variable length type as below

```
    from netCDF4 import Dataset
    f = Dataset(""example.nc"",""w"")
    vlen_t = f.createVLType(numpy.int32, ""phony_vlen"")
    x = f.createDimension(""x"",3)
    y = f.createDimension(""y"",4)
    vlvar = f.createVariable(""phony_vlen_var"", vlen_t, (""y"",""x""))
    data =[]
    for n in range(0, len(x)*len(y)):
        data.append(numpy.arange(random.randint(1,10),dtype=""int32""))
    data = numpy.reshape(data,(len(y),len(x)))
    vlvar[:] = data
    f.close()
```
Using files generated this way, I did not get an error using mf_dataset. 

","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,457874038
https://github.com/pydata/xarray/issues/3034#issuecomment-514054766,https://api.github.com/repos/pydata/xarray/issues/3034,514054766,MDEyOklzc3VlQ29tbWVudDUxNDA1NDc2Ng==,1217238,2019-07-23T05:01:49Z,2019-07-23T05:01:49Z,MEMBER,"Thanks @HasanAhmadQ7, that would be fantastic !","{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,457874038
https://github.com/pydata/xarray/issues/3034#issuecomment-514049445,https://api.github.com/repos/pydata/xarray/issues/3034,514049445,MDEyOklzc3VlQ29tbWVudDUxNDA0OTQ0NQ==,32473508,2019-07-23T04:28:58Z,2019-07-23T04:28:58Z,CONTRIBUTOR,I will handle this issue this Saturday if no one else handle it by then.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,457874038
https://github.com/pydata/xarray/issues/3034#issuecomment-504034289,https://api.github.com/repos/pydata/xarray/issues/3034,504034289,MDEyOklzc3VlQ29tbWVudDUwNDAzNDI4OQ==,1217238,2019-06-20T13:52:29Z,2019-06-20T13:52:29Z,MEMBER,"We could probably fix this by adding another case to `equivalent` for lists, e.g,.
```python
elif isinstance(first, list) or isinstance(second, list):
    # verify both first and second are lists of the same length with the same elements
    # (by calling equivalent() on all elements)
```

Any interest in putting together a pull request for this? See http://xarray.pydata.org/en/stable/contributing.html","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,457874038