import re
import random

WORDS = ["Brawk" , "Buh-gok", "Bok bok", "Bawk"] # My random word list
PATTERN = r"(\[[^][]*]|\{[^{}]*})|[a-zA-Z0-9']+"
DELIMITER = " "

def callback(matchobj):
    return matchobj.group(1) or random.choice(WORDS)

def parse_sentence(sentence):
    return re.sub(PATTERN, callback, sentence)

print(parse_sentence("some text's[color=#ff8a00]smoe more text[/color]{n}"))