April 2018
Beginner
340 pages
7h 54m
English
Since these variables are objects, we cannot assign to them a statement like label_text = "Hello World!". Instead, each variable exposes a get and set method. Let's have a play with these in the interactive shell:
>>> from tkinter import * >>> win = Tk() >>> sv = StringVar() >>> sv <tkinter.StringVar object at 0x05F82D50> >>> sv.get() '' >>> sv.set("Hello World!") >>> sv.get() 'Hello World!' >>> sv.set(sv.get() + " How's it going?") >>> sv.get() "Hello World! How's it going?"
These variables are passed to widgets inside their keyword arguments upon creation (or at a later stage, using configure). The keyword arguments expecting these special variables will usually end in var. In the case of a label, the argument is textvar ...