[noncovalence]

As others have pointed out, tkinter is just a wrapper around Tk, so the best way to learn more about it is to learn about Tk. The documentation for Tk [1] is fairly comprehensive: for example, the algorithm used by the `pack` command that you asked about is explained here: [2].

It's definitely worth learning at least some very basic Tcl if you want to get as much as possible out of tkinter - sometimes you end up having to use `widget.tk.eval()` to use a Tk feature that tkinter doesn't provide a good wrapper for.

[1] https://www.tcl.tk/man/tcl/TkCmd/contents.html [2] https://www.tcl.tk/man/tcl/TkCmd/pack.htm#M27