asciify unicode strings within the files. I didn't have time to test it properly. If you find a bug, just tell me.

asciify.py

# [X] Reading from file
# [X] Splitting word by word
# [X] Split ascii and unicode
# [X] Determine a range and apply filter
# [X] Collect all the unique ones in an array
# [X] Create random english words for them
# [X] Create an updated file
# [ ] Work with folder and file as a input

#!/usr/bin/python
# encoding: utf-8

import sys
import urllib2
from random import randint

if len(sys.argv) < 2:
    print("Please enter file to asciify!")
    exit()


def checkUnique(string, arrayUni):
    place = -1
    for i, uni in enumerate(arrayUni):
        if len(uni) is not len(string):
            continue
        else:
            for index in range(len(uni)):
                if uni[index] is not string[index]:
                    break
                elif index is len(uni) - 1:
                    place = i
                    break
        if place is not -1:
            break
    return place
       
def addToArrays(arrayUni, word, arrayRand, words):
    if word is not "":
        arrayUni.append(word)
        arrayRand.append(words[randint(0, len(words) - 1)])

# https://stackoverflow.com/questions/18834636/random-word-generator-python
word_site = "http://svnweb.freebsd.org/csrg/share/dict/words?view=co&content-type=text/plain"

response = urllib2.urlopen(word_site)
txt = response.read()
WORDS = txt.splitlines()

arrayUni = []
arrayRand = []
uniStr = ""

start = -1
end = -1

file = open("rep_" + sys.argv[1], 'w')

with open(sys.argv[1],'r') as f:
    for line in f:
        for word in line.split():
            for i, char in enumerate(word):
                if ord(char) > 127:
                    if start is -1:
                        start = i
                elif ord(char) is 46 or ord(char) is 40 or ord(char) is 41 or ord(char) is 59:
                    if start is not -1: 
                        end = i
                        uniStr = word[start:end]
                        check = checkUnique(uniStr, arrayUni)
                        if check is -1:
                            addToArrays(arrayUni, uniStr, arrayRand, WORDS)
                            line = line.replace(uniStr, "rep_" + arrayRand[len(arrayRand) - 1])
                        else:
                            line = line.replace(uniStr, "rep_" + arrayRand[check])
                        start = -1
                        end = -1
            if start is not -1 and end is -1:
                end = i
                uniStr = word[start:end]
                check = checkUnique(uniStr, arrayUni)
                if check is -1:
                    addToArrays(arrayUni, uniStr, arrayRand, WORDS)
                    line = line.replace(uniStr, "rep_" + arrayRand[len(arrayRand) - 1])
                else:
                    line = line.replace(uniStr, "rep_" + arrayRand[check])
            start = -1
            end = -1
        file.write(line)
file.close()