Python IDLE auto expand for instantiated objects

Question

I'm learning GUIs with tkinter, and I've been using the autocomplete function built into IDLE so that I don't constantly have to go looking into documentation for methods pertaining to certain objects/classes.

However I'm having a problem wherein IDLE's autocomplete feature does not work with instantiated classes/objects. For example, in the IDLE editor (not the interactive shell):

import tkinter
from tkinter import ttk

root = tkinter.Tk()
root.title('Some title')

if I type in "tkinter.Tk." and then press ctrl+space, it brings up the autocomplete suggestion menu just fine, however if I type "root." and then press ctrl+space, nothing happens. Why is this?

Answer 1

In order to look up attributes on an object, the object must exist. Currently, IDLE's autocomplete does not create new objects for autocompletion. Suppose you interactively type

>>> import tkinter
>>> root = tkinter.Tk()
>>> root.

The first line makes sure that module tkinter exists in the user process space. The second line create a root object. Autocompletion for the third line uses the new root object.

If you type the same 3 lines in an editor, no code is executed until you hit F5. Autocompletion is limited to whatever objects exist in the user process because of the user process startup code (in idlelib/run.py) plus whatever code has already been run since the last reset. It happens that tkinter is (currently) imported by run.py. So tkinter. autocompletes. However, there is no root object.

The user solution is to run your incomplete code frequently to import modules and create instances. If you hit F5 after the second line and return to the editor, then root. will autocomplete, as in the Shell.