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/pull/1682#issuecomment-365842057,https://api.github.com/repos/pydata/xarray/issues/1682,365842057,MDEyOklzc3VlQ29tbWVudDM2NTg0MjA1Nw==,1217238,2018-02-15T07:04:56Z,2018-02-15T07:04:56Z,MEMBER,"@ajelenak-thg thanks for your patience here. I need to think a little bit harder about what the right API for controlling the default engine is, but this work is definitely appreciated (and will probably make it in for the next release).","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,270677100
https://github.com/pydata/xarray/pull/1682#issuecomment-348155004,https://api.github.com/repos/pydata/xarray/issues/1682,348155004,MDEyOklzc3VlQ29tbWVudDM0ODE1NTAwNA==,1217238,2017-11-30T10:58:20Z,2017-11-30T10:58:20Z,MEMBER,"One more minor complexity is that there are two version of netCDF, not all of which are supported by all tools:

- netcdf4 support netcdf3 and netcdf4
- scipy only supports netcdf3
- h5netcdf only supports netcdf4.
- pynio supports both netcdf3 and netcdf4.

So will need to distinguish between URLs (opendap) and these two types of netCDF files. To do this, we'll need to look at the first few bytes of each file:
- netCDF4/HDF5 starts with the 8-byte signature `b'\x89HDF\r\n\x1a\n'`
- netCDF4 starts with `b'CDF\x00'` or `b'CDF\x01'`","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,270677100
https://github.com/pydata/xarray/pull/1682#issuecomment-341795047,https://api.github.com/repos/pydata/xarray/issues/1682,341795047,MDEyOklzc3VlQ29tbWVudDM0MTc5NTA0Nw==,1217238,2017-11-03T18:51:49Z,2017-11-03T18:51:49Z,MEMBER,"Maybe it would make more sense to set a list of engines to try in order? e.g., `io_engines=['pydap', 'h5netcdf', 'scipy']` could use pydap for web requests, h5netcdf for netCDF4 and scipy for netCDF3. The default would be something like `['netcdf4', 'pydap', 'scipy', 'h5netcdf']`","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,270677100
https://github.com/pydata/xarray/pull/1682#issuecomment-341613287,https://api.github.com/repos/pydata/xarray/issues/1682,341613287,MDEyOklzc3VlQ29tbWVudDM0MTYxMzI4Nw==,1217238,2017-11-03T03:04:17Z,2017-11-03T03:04:17Z,MEMBER,We should probably have separate options for opendap/netcdf. It would not be so useful to try to use pydap to read a netcdf file.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,270677100
https://github.com/pydata/xarray/pull/1682#issuecomment-341586491,https://api.github.com/repos/pydata/xarray/issues/1682,341586491,MDEyOklzc3VlQ29tbWVudDM0MTU4NjQ5MQ==,1217238,2017-11-02T23:19:55Z,2017-11-02T23:19:55Z,MEMBER,"I like the direction this is going in, but as @MaximilianR notes it won't work to set this in default function arguments.

Also, I would probably pick a more descriptive name for the option, e.g., `netcdf_engine`.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,270677100
https://github.com/pydata/xarray/pull/1682#issuecomment-341577210,https://api.github.com/repos/pydata/xarray/issues/1682,341577210,MDEyOklzc3VlQ29tbWVudDM0MTU3NzIxMA==,5635139,2017-11-02T22:29:45Z,2017-11-02T22:29:45Z,MEMBER,"This looks great so far!

But have you tested this? I have a suspicion that putting `OPTIONS['engine']` as a default arg won't work: whenever the relevant function is imported, the default will be set to the value at that time, and won't change if the options dictionary is later modified. 

You could have a default arg of `None` and then look up the option within the function, if my suspicions are right
","{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,270677100