MyBinder allows running Python notebooks from github repos, and it’s free at least now when it’s in beta.
To prepare a repo it’s enough to add one text file for listing dependencies. See instructions here http://mybinder.readthedocs.io/en/latest/using.html
After this go to mybinder.org and enter your repo address and possible branch and path. MyBinder makes a docker image and runs it in their server. You can also share a link and docker images are stored so that it’s fast to try a ready made binder.
You can try running Python notebooks in my BDA course notebook collections (there are also couple PyStan notebooks there)