Matching whole words in find/replace script

[greektranslator]

I use the code below through Notepad++ but I cannot make it match whole words

with open('C:/Temp/Substitutions.txt') as f:
    for l in f:
        s = l.split()
        editor.replace(s[0], s[1])

I also tried:

editor.pyreplace(r'\b' + s[0] + r'\b', s[1])

and

editor = re.sub(r'\b' + s[0] + r'\b', s[1], editor)