PyQt - Riverbank | Software | PyQt | What is PyQt?
GTK - GTK+ is a multi-platform toolkit for creating graphical user interfaces.
Dear PyGui - Dear PyGui is a simple to use (but powerful) Python GUI framework. Dear PyGui provides a wrapping of Dear ImGui which simulates a traditional retained mode GUI (as opposed to Dear ImGui's immediate mode paradigm).
PySimpleGUI - A simple to use GUI that can create custom GUIs
wxWidgets - wxWidgets: Cross-Platform GUI Library
MD Python Designer - A drag and drop GUI Designer that uses a combination of Tkinter and its own code.