How do I effectively make changes to a 3rd party django app?
You can modify your 3rd party app by uninstalling it using pip uninstall, then copying (or git cloning) the app into your source tree. You may need to temporarily add a line like sys.path.append("./django-leaflet") to your manage.py file so that the 3rd party modules will be in scope.
Once you are happy with your changes, you can send them to the original author as a pull request or upload your own version of the app.
I am working on a Django application which uses django-leaflet, but this question applies to any python library. I want to change some django-leaflet code to see if the changes would solve a problem we are having. What are my options? Do I need to create an example app in the django-leaflet repository and preform my modify-test loop there? Or do I need to upload individual re-named versions of django-leaflet to pypi?