Do you want to develop a web application that can obtain details about the web browser? If you are using the Django web framework for Python, you can use the Django User Agents package from https://pypi.python.org/pypi/django-user_agents
The browser sends some information within an HTTP request, and you can write Javascript to obtain the other information and pass it back to the web server.
If you want to develop a desktop application, you can obtain Internet Explorer settings from the Windows registry, for which we have the winreg Python module. Firefox settings are stored in a prefs.js file. You can similarly find the location of the settings for other web browsers to read their settings.