Recently, I found a open source ERP application project which was developed by python and django framework. Prometeo is absolutely an open-source and free of charge. It is very user friendly and user-oriented, too.
1. Checkout sources from the GIT repository:
git clone https://firstname.lastname@example.org/p/prometeo-erp/ prometeo
2. Follow the instructions in the README file from the download.
3. Test the installation at http://localhost:8000 running the development server:
python manage.py runserver
This Prometeo-ERP project is no longer maintained nor supported! However, it is succeeded by another project called django ERP, which is still under developing. Its link is –> https://github.com/djangoERPTeam/django-erp