I'm trying to understand some aspects of the Python TKinter package. The package root cpython/Lib/tkinter is found on GitHub. I'm looking at the file cpython/Lib/tkinter/ttk.py. At line 512, this file defines a Widget class: 28 import tkinter ... 512 class Widget(tkinter.Widget): """Base class for Tk themed widgets.""" Figuring out what this is doing requires identifying this imported tkinter package. According to the Python docs, a directory containing a file __init__.py constitutes a regular package. Since [cpython/Lib/tkinter/__init__.py] exists, the directory cpython/Lib/tkinter/ is a regular package. My understanding is that when interpreting import tkinter, the current directory is one of the first places Python will look for a package (though that understanding is difficult to verify from the "Searching" portion of the docs). If true, then what's imported by the import tkinter line of cpython/Lib/tkinter/ttk.py is the folder cpython/Lib/tkinter/ itself. Since the file cpython/Lib/tkinter/ttk.py is the only place where a Widget class is defined in this directory (at least as far as I can tell from the GitHub search function), then it appears that the code in cpython/Lib/tkinter/ttk.py 28 import tkinter ... 512 class Widget(tkinter.Widget): """Base class for Tk themed widgets.""" defines a class that extends itself. Surely there's something I don't understand. What is going on here? Continue reading...
