This directory is intended to act as a placeholder for extending ReportLab with extra extensions. It has been packagised with an empty __init__.py. So a typical extender should add his package extension as reportlab/extensions/great_extension/__init__.py /dingo.py /etc etc and single modules as reportlab/extensions/my_module.py Then client code can do from reportlab.extensions.great_extension import dingo if you extend with just a single module it might be simpler to add that into extensions so that you could do from reportlab.extensions import my_module. ReportLab can take no responsibility for name clashes and problems caused by modules and packages in reportlab/extensions.