Turning Tcl scripts into Python

We can …

Convert a Tcl script of any size into a valid Python script in just two minutes.

A one-line example

hello.tcl

 puts "Greetings from Tcl [info patchlevel]"

 > tclsh hello.tcl
 Greetings from Tcl 8.6.7

What support is available?

Let's look at our Python installation.

Windows' Python installation

  > dir D:\Python36
…
  2017-01-24  06:06             python.exe
…
  2017-08-07  16:34    <DIR>    tcl
…

Drill down

  > dir D:\Python36\tcl
…
  2017-08-07  16:35    <DIR>    tcl8.6
…
  2017-08-07  16:35    <DIR>    tk8.6
…

Why does Python ship Tcl?

Because of Tk, which Python provides via its Tk interface package:  tkinter

Since it does ship Tcl …

Write a Python wrapper: hello.py

 import sys ; import tkinter
 print("Greetings from Python {0}.{1}.{2}".
       format(*sys.version_info))
 gui = tkinter.Tk()
 gui.tk.eval(open('hello.tcl', 'r').read())
 # if a Tk application, add: gui.mainloop()

We now have valid Python

 > python3 hello.py
 Greetings from Python 3.6.0
 Greetings from Tcl 8.6.7

Success!

• valid Python script
• equivalent to the Tcl script
• O(1) "re-write" for n lines of Tcl code

Works for Python 2, if you capitalize Tkinter and use print statements.

Motivation

• to have fun
• to encourage others to have fun
• to get the word out that Tcl is fun

  {expand}"Team Tcl"

{*}"Team Tcl"

Buzzwords

• Tcl, Tk, Tcl/Tk
• Python, Python 2, Python 3, tkinter
• rapid prototyping, innovation
• lightning talk, code translation
• U-boat project, fun, trick, joke, koan

See Also

• Python, tip given in "Description" section
• Accessing Tcl and Python from one another
• How Tkinter can exploit Tcl/Tk extensions

Python 2.7

 import Tkinter
 gui = Tkinter.Tk()
 gui.tk.eval(open('hello.tcl', 'r').read())
 if False: gui.mainloop()
      

 > python2 hello2.py
 Greetings from Tcl 8.5.15

Python 3.6

 import tkinter
 gui = tkinter.Tk()
 gui.tk.eval(open('hello.tcl', 'r').read())
 if False: gui.mainloop()
      

 > python3 hello3.py
 Greetings from Tcl 8.6.6