convert_bindsyms.py

#!/usr/bin/env python3

import sys
import pprint
import re
import subprocess

def get_mapping():
    p = subprocess.Popen(["xmodmap", "-pke"], stdout=subprocess.PIPE)

    keysym_to_code = {}

    for line in p.stdout:
        line = line.decode('ascii').strip()

        keycode, keysyms = line.split("=") 

        keycode = keycode.strip()
        keysyms = keysyms.strip().split()

        keycode = int(re.match('^keycode +(\d+)$', keycode).group(1) )

        for keysym in keysyms:
            keysym_to_code[keysym] = str(keycode)

    p.wait()

    return keysym_to_code

def process_bindsym(line, keysym_to_code):
    args = line.split(" ")
    assert args[0] == "bindsym"
    
    args[0] = "bindcode"
    args[1] = args[1].split("+")
    args[1][-1] = keysym_to_code[args[1][-1]]
    args[1] = "+".join(args[1])

    line = " ".join(args)
    return line

def main():
    keysym_to_code = get_mapping()

    #pprint.pprint(keysym_to_code)

    for line in sys.stdin:
        line = line.rstrip("\n")
        
        # preserve whitespace indentation
        m = re.match("^( *)(bindsym.*)$", line)
        if m:
            print(m.group(1) + "#-- " + m.group(2))
            print(m.group(1) + process_bindsym(m.group(2), keysym_to_code))
        else:
            print(line)

if __name__ == "__main__":
    main()

Some of my bindsym's had no matching bindcode so I added a try...except block. I also tweaked the script so that its output can be piped through another instance. So I can keep just one config file. You can see the result here.