Python GUI

I need a simple GUI written in Python. The purpose of the GUI is to provide a front-end for codes I have written. It is very important that the code be simple and easy for me to understand, because its purpose is to serve as a framework for further development, not a finished product. GUI Requirements: - A sidebar for directory navigation and file management on the left side of the screen. The user finds, saves and loads files using this interface. - A "main" work area which can open working documents. Working documents may be: Text files, which can be viewed and edited. Interactive graphical images. For example, graphs made by the python library matplotlib. As part of verifying that the GUI works I will need to be able to open previously saved graphics and text files. - The standard "File | Edit | Format | View | Help" bar across the top. These pulldown menus only need minimal options at this point. - A "console" across the bottom of the screen. This will simply allow the user to input text commands which are captured and can be interpreted later. No interpreter for the commands is required, just the ability to enter commands. Use as a design example something like FreeCAD, except much simpler.