Am trying to execute a Python script from node. It's hitting the endpoint, and runs fine locally but when I try deploy from Heroku, I get the following error log:
```
2018-10-10T01:00:14.689410+00:00 app[web.1]: events.js:183
2018-10-10T01:00:14.689416+00:00 app[web.1]: throw er; // Unhandled 'error' event
2018-10-10T01:00:14.689417+00:00 app[web.1]: ^
2018-10-10T01:00:14.689419+00:00 app[web.1]:
2018-10-10T01:00:14.689421+00:00 app[web.1]: Error: spawn python3.6 ENOENT
2018-10-10T01:00:14.689424+00:00 app[web.1]: at Process.ChildProcess._handle.onexit (internal/child_process.js:190:19)
2018-10-10T01:00:14.689426+00:00 app[web.1]: at onErrorNT (internal/child_process.js:362:16)
2018-10-10T01:00:14.689428+00:00 app[web.1]: at _combinedTickCallback (internal/process/next_tick.js:139:11)
```
I tried setting the Python runtime in runtime.txt in the root directory:
```
$ cat runtime.txt
python-3.6.0
```
To answer my own question, the reason was I needed to add the Python buildpack alongside the NodeJS buildback. Discussed here: https://stackoverflow.com/a/39947385/3268182