Pygubu

Pygubu is a rapid application development (RAD) tool for Python that enables developers to design graphical user interfaces (GUIs) visually using the Tkinter toolkit, without writing layout code by hand. Created by Alejandro Autalan, Pygubu consists of two components: the Pygubu Designer, a visual drag-and-drop GUI builder application where developers create interface layouts by placing and configuring widgets on a canvas, and the Pygubu runtime library, which loads the generated UI definition files (XML format) at runtime and constructs the Tkinter interface. The designer supports the standard Tkinter widget set including Button, Label, Entry, Text, Frame, Canvas, Listbox, Combobox, Checkbutton, Radiobutton, Scale, Scrollbar, Notebook, Treeview, PanedWindow, Menu, Menubutton, Spinbox, LabelFrame, Progressbar, Separator, Sizegrip, and ttk themed widgets, as well as custom widgets through a plugin system. Layout management uses Tkinter's three geometry managers: pack, grid, and place, all configurable through the designer interface. Pygubu generates project files in a structured XML format (.ui files) that define widget hierarchy, properties, bindings, and layout parameters, which can be version-controlled and edited independently of application logic. The runtime library provides an event binding API that connects widget events to Python callback functions, and supports custom widget registration for extending the designer with third-party components. Pygubu is cross-platform, running on Windows, Linux, and macOS wherever Python and Tkinter are available. The project has over 1,400 GitHub stars and is available under the GPLv3 license.