How to determine what version of python3 tkinter is installed on my linux machine?

Previous answers describe tkinter.TclVersion and tkinter.TkVersion that provide the major and minor Tcl/Tk versions but not the patch number.

To get the full version in the major.minor.patch format, you could use the info patchlevel Tcl command.

For example:

import tkinter

tcl = tkinter.Tcl()
print(tcl.call("info", "patchlevel"))

# Output:
# 8.6.10

To do the same from a Tkinter app, which already has an associated Tcl interpreter, you could run this instead:

import tkinter

root = tkinter.Tk()
...
print(root.tk.call("info", "patchlevel"))

# Output:
# 8.6.10

Type this command on the Terminal and run it.

python -m tkinter

A small window will appear with the heading tk and two buttons: Click Me! and QUIT. There will be a text that goes like This is Tcl/Tk version ___. The version number will be displayed in the place of the underscores.

You cal so invoke TclVersion:

>>> import tkinter
>>> tkinter.TclVersion
8.6

Tested for Python 3.6.5 and Python 3.5.2 (Ubuntu 16.04.4):

In the terminal try as follows:

python -m tkinter or python3 -m tkinter