David Zülke
acd9347930
The Node buildpack now exports a leading zero in its numbers. This lets us detect that it (or another buildpack) set the value, and overwrite it accordingly. Fixes the issue where adding the node buildpack to a Python app would cause only one gunicorn worker to be spawned for a 1X dyno, and not two. We also need to again produce leading zeroes in the value, so that e.g. the PHP buildpack can do the same on boot.
Heroku Buildpack: Python
This is the official Heroku buildpack for Python apps, powered by pip and other excellent software.
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.
See it in Action
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
Specify a Python Runtime
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-2.7.13python-3.6.0pypy-5.6.0(unsupported, experimental)pypy3-5.5.0(unsupported, experimental)