Importing tkinter doesn't import some basic and useful modules such as messagebox, as explained here: tkinter.messagebox.showinfo doesn't always work
How do I check which modules are actually imported with import tkinter and which ones can be potentially imported by importing them explicitly (e.g. from tkinter import messagebox)?
How do I check which modules are actually imported with import tkinter?
Use this code example to check all that is imported with tkinter:
import tkinter as tk
help(tk)
You will get a large amount of data printed to the console that shows all the imports and "constants" that are imported with *.
If you take the time to read the tkinter documentation you will see a section that says the following:
Other modules that provide Tk support include:
tkinter.scrolledtext Text widget with a vertical scroll bar built in.
tkinter.colorchooser Dialog to let the user choose a color.
tkinter.commondialog Base class for the dialogs defined in the other modules listed here.
tkinter.filedialog Common dialogs to allow the user to specify a file to open or save.
tkinter.font Utilities to help work with fonts.
tkinter.messagebox Access to standard Tk dialog boxes.
tkinter.simpledialog Basic dialogs and convenience functions.
tkinter.dnd Drag-and-drop support for tkinter.
This is experimental and should become deprecated when it is replaced with the Tk DND. turtle Turtle graphics in a Tk window.
This section contains all the other commonly needed imports that do not get imported with *. One that does not seam to be listed in this section that I believe should be is ttk. The ttk imports are also separate from *.
For ttk imports you can use fancy looking buttons and other widgets that all use a common style that can be set in the code as well. It is visually nice to use but not 100% needed in the work that is done in the GUI.