wp user get
wp user get <user> [--field=<field>] [--fields=<fields>] [--format=<format>]
Examples
# Get user
$ wp user get 12 --field=login
supervisor
# Get user and export to JSON file
$ wp user get bob --format=json > bob.json
wp user get <user> [--field=<field>] [--fields=<fields>] [--format=<format>]