To install just do
pip install https://github.com/segasai/desi_retriever/archive/master.zip
You also need to set-up the DESI user/password. You need to put the login password in the file $HOME/.desi_http_user in the format login:password
Then to fetch a given spectrum from coadd you can do
D = desi_retriever.andes.get_specs( tileid=63075, night=20200219, fiber=0, targetid=35190987189916575, coadd=True)
or to get list of multiple exposures
D = desi_retriever.andes.get_specs(tileid=63075, night=20200219, fiber=0, targetid=35190987189916575)
You could also get the RVSpecFit models by using
Dmod = desi_retriever.andes.get_rvspec_models( tileid=63075, night=20200219, fiber=0, targetid=35190987189916575,coadd=True)
More examples are in jupyter notebooks in example folder