I have a Django app I want to deploy to Heroku. I tried to follow the instructions here: https://devcenter.heroku.com/articles/getting-started-with-django which tells you to
I had this problem too.
I wanted to deploy a django app which use numpy, sckit-learn and some other conda packages.
I used the conda-buildpack but the installed packages weren't accessible from inside django. So I created a fork which extended the PYTHONPATH and removed the part where dependencies installed withpip install -r requirements.txt because this part clashed with memcached on heroku.
Now I have a multiple buildpack setup
with the default heroku python buildpack and my custom condas buildpack fork
The requirements.txt is processed by the python buildpack and the conda-requirements.txt by the conda buildpack. Works like a charm for me.