Netrc: Managing your login credentials

.netrc is a file that contains login information for various servers. It’s used by programs that need to log in to servers. You can add login information to a .netrc file in your home to avoid supplying username and password each time you download data.

DataDownloader provides a Netrc class to manage your .netrc file. The details of the class can be found here.

Following codes show how to using the Netrc class to manage your .netrc file.

Import and create a Netrc object

from data_downloader import downloader

netrc = downloader.Netrc()
netrc.hosts

{}

Add a new credential record

netrc.add("urs.earthdata.nasa.gov", "username", "passwd")
netrc.hosts

{'urs.earthdata.nasa.gov': ('username', '', 'passwd')}

The new record is added to the .netrc file in the user’s home directory. For Linux and MacOS, the file is located at ~/.netrc. For Windows, the file is located at %HOME%\.netrc.

!cat ~/.netrc

machine urs.earthdata.nasa.gov
	login username
	password passwd

If the record already exists, you need set overwrite=True to overwrite it.

netrc.add("urs.earthdata.nasa.gov", "username", "passwd_new", overwrite=True)
netrc

machine urs.earthdata.nasa.gov
	login username
	password passwd_new

Get the host from the url

If you don’t know the host of the server, you can use the get_url_host function to get it by the url.

url = "https://gpm1.gesdisc.eosdis.nasa.gov/daac-bin/OTF/HTTP_services.cgi?FILENAME=%2Fdata%2FGPM_L3%2FGPM_3IMERGM.06%2F2000%2F3B-MO.MS.MRG.3IMERG.20000601-S000000-E235959.06.V06B.HDF5&FORMAT=bmM0Lw&BBOX=31.904%2C99.492%2C35.771%2C105.908&LABEL=3B-MO.MS.MRG.3IMERG.20000601-S000000-E235959.06.V06B.HDF5.SUB.nc4&SHORTNAME=GPM_3IMERGM&SERVICE=L34RS_GPM&VERSION=1.02&DATASET_VERSION=06&VARIABLES=precipitation"

downloader.get_url_host(url)

'gpm1.gesdisc.eosdis.nasa.gov'

netrc.add(downloader.get_url_host(url), "username", "passwd")
netrc

machine urs.earthdata.nasa.gov
	login username
	password passwd
machine gpm1.gesdisc.eosdis.nasa.gov
	login username
	password passwd

Remove credential records

If you want to remove a record from the .netrc file, you can use the remove method.

netrc.remove(downloader.get_url_host(url))
netrc

machine urs.earthdata.nasa.gov
	login username
	password passwd

If you want to remove all records from the .netrc file, you can use the clear method.

netrc.clear()
netrc