This takes all the Hearthstone tournaments from http://showdowngg.challonge.com and takes all the matches and uses Trueskill to calculate an Elo for each player.
With some tweaking it should be able to be used with other tournaments as well.
You'll need to create a file called config.py in order to use this. A sample one is below. You'll need to get an API key from here.
user: '<challonge username>'
api_key: '<API key>'
subdomain: '<challonge subdomain. I used showdowngg for this>'