by richgong

GitHub Readme.md

Richard Gong's note on this fork

I'm using PyCall (calling from Ruby) for Heroku Python.

Heroku's buildpack has a known issue with PyCall: https://github.com/mrkn/pycall.rb/issues/62

To fix, I've forked this buildpack to use --enable-shared in the Python build: https://github.com/richgong/heroku-buildpack-python/commit/43874f65a387c158d548c0f1191ed37f8d7cb068

Similar to here: https://github.com/mrkn/pycall.rb/blob/c282d62aa0756bf4e71c570822d4c2be2957d442/docker/Dockerfile#L52

Heroku Buildpack: Python


Build Status

This is the official Heroku buildpack for Python apps.

Recommended web frameworks include Django and Flask, among others. 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.

Python packages with C dependencies that are not available on the stack image are generally not supported, unless manylinux wheels are provided by the package maintainers (common). For recommended solutions, check out this article for more information.

See it in Action

$ ls
my-application		requirements.txt	runtime.txt

$ git push heroku master
Counting objects: 4, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (4/4), 276 bytes | 276.00 KiB/s, done.
Total 4 (delta 0), reused 0 (delta 0)
remote: Compressing source files... done.
remote: Building source:
remote: -----> Python app detected
remote: -----> Installing python-3.7.1
remote: -----> Installing pip
remote: -----> Installing SQLite3
remote: -----> Installing requirements with pip
remote:        Collecting flask (from -r /tmp/build_c2c067ef79ff14c9bf1aed6796f9ed1f/requirements.txt (line 1))
remote:          Downloading ...
remote:        Installing collected packages: Werkzeug, click, MarkupSafe, Jinja2, itsdangerous, flask
remote:        Successfully installed Jinja2-2.10 MarkupSafe-1.1.0 Werkzeug-0.14.1 click-7.0 flask-1.0.2 itsdangerous-1.1.0
remote: -----> Discovering process types
remote:        Procfile declares types -> (none)

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

To specify your python version, you also need a runtime.txt file - unless you are using the default Python runtime version.

Current default Python Runtime: Python 3.6.7

Alternatively, you can provide a setup.py file, or a Pipfile. Using Pipenv will generate runtime.txt based on python-version at build time.

Specify a Buildpack Version

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

$ heroku buildpacks:set heroku/python

Specify a Python Runtime

Supported runtime options include:

  • python-3.7.1
  • python-3.6.7
  • python-2.7.15


The buildpack tests use Docker to simulate Heroku's stack images.

To run the test suite:

make test

Or to test in a particular stack:

make test-heroku-18
make test-heroku-16

The tests are run via the vendored shunit2 test framework.