To install or update - pip3 install --upgrade user_agent_scraper
You can view all possible browsers here.
import user_agent_scraper - Imports the module, but I think you know what this does already.
user_agent_scraper.scrape_valid_browsers() - Get all browsers, returned in an array
user_agent_scraper.scrape_user_agents(browsers) - Gets all user agents for the browsers passed into an array