Recommended web frameworks include Django and Flask. The recommended webserver is Gunicorn. There are no restrictions around what software can be used (as long as it's pip-installable). Web processes must bind to $PORT, and only the HTTP protocol is permitted for incoming connections.

Some Python packages with obscure C dependencies (e.g. scipy) are not compatible.

Deploying a Python application couldn't be easier:

$ ls
Procfile  requirements.txt  web.py

$ heroku create --buildpack heroku/python

$ git push heroku master
...
-----> Python app detected
-----> Installing python-2.7.13
     $ pip install -r requirements.txt
       Collecting requests (from -r requirements.txt (line 1))
         Downloading requests-2.12.4-py2.py3-none-any.whl (576KB)
       Installing collected packages: requests
       Successfully installed requests-2.12.4
       
-----> Discovering process types
       Procfile declares types -> (none)

A requirements.txt file must be present at the root of your application's repository.

You can also specify the latest production release of this buildpack for upcoming builds of an existing application:

$ heroku buildpacks:set heroku/python

Specific versions of the Python runtime can be specified with a runtime.txt file:

$ cat runtime.txt
python-3.6.0

Runtime options include:

• python-2.7.13
• python-3.6.0
• pypy-5.6.0 (unsupported, experimental)
• pypy3-5.5.0 (unsupported, experimental)