Passing a Variable from Python script to tcl shell

Question

I am new to this forum, so I apologize beforehand for any mistakes. I am trying to pass a variable from my python code to tcl script. The way I am doing this is:

import os
import Tkinter
from Tkinter import *
def set_impairments(port,delay):
 port=int(port)
 delay=int(delay)
 tcl = Tcl()
 tcl.eval("""
 proc my_proc {in_port,in_delay} {
 puts in_port
 puts in_delay
 }
 """)
 print port
 print delay
 tcl.eval('my_proc port,delay')
set_impairments(0,25000)

The output of this code is:

0
25000
in_port
in_delay

How to assign in_port to 0 and in_delay to 25000? I am not able to understand why it is not able to pass the value of the variable.

• schlenk: This is partially a duplicate of stackoverflow.com/questions/25288972/… but you can also use the 'eval' + format solution below instead of using a Tkinter StringVar.
• wolf123: Yeah I have gone through that thread and it didn't help me. Apparently I was missing the point as Glenn suggested to put a $ to reference the value of the variable. Anyway Thanks.

Answer 1

Tcl doesn't use commas to separate arguments, it uses whitespace. Also, you need a $ to reference the value of the variable. Do this:

proc my_proc {in_port in_delay} {
 puts $in_port
 puts $in_delay
}

I'm not really a python guy, but you probably want

tcl.eval('my_proc {0} {1}'.format(port,delay))

• schlenk: One can write the call a bit nicer as tcl.call('my_proc', port, delay) which has a bit of magic so you do not need to move through the string rep. Does not work for all python variable types though, but int / string works.
• wolf123: Thank you so much Glenn.This helped.
• wolf123: Thank You Schlenk. I will definitely look at it.