Is it possible to open multiple files at once?

[ledm]

Hi again, sorry to be a pesky user, but our version of nemo splits out a file every month, so we need to open several different files if we want to generate a climatology or an annual mean, for instance. What is the best method for multiple gridded files at once in COAsT?

I've tried using wildcards, but get the error:

a = coast.gridded('path/to/files/*.nc')
...
[Errno 2] No such file or directory: b'

I've also tried passing a list of files to gridded asnd get this error:

a = coast.gridded(['path/to/files/file1.nc', 'path/to/files/file2.nc'] )
...
ValueError: did not find a match in any of xarray's currently installed IO backends ['netcdf4', 'scipy', 'pydap']. Consider explicitly selecting one of the installed engines via the ``engine`` parameter, or installing additional IO dependencies, see:
https://docs.xarray.dev/en/stable/getting-started-guide/installing.html
https://docs.xarray.dev/en/stable/user-guide/io.html

I've also thought maybe it would be possible to open the files one at a time and then somehow merge the gridded datasets? But I can't see any function that would do that explicitly defined in the documentation:

https://british-oceanographic-data-centre.github.io/COAsT/docs/reference/gridded/

What is the best method for multiple gridded files at once in COAsT?