Comment déployer une application python CGI sur Heroku

remote:  !     No default language could be detected for this app.
remote:                         HINT: This occurs when Heroku cannot detect the buildpack to use for this application automatically.
remote:                         See [https://devcenter.heroku.com/articles/buildpacks]
remote:
remote:  !     Push failed
remote: Verifying deploy...
remote:
remote: !       Push rejected to ggb-app-gen.
remote:
To [https://git.heroku.com/ggb-app-gen.git]
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com/ggb-app-gen.git'