dotsfile = open('dots.txt', 'r')
wantedfile = open('wanted.txt', 'r')
keywordsfile = open('keywords.txt', 'w')
instructionsfile = open('instructions.txt', 'r')

def commandStrip(sentence):
    for line in dotsfile:
        sentence = sentence.replace(line.strip('\n'), '')
    return sentence

def searchKeyWords(sentence):
    found = []
    for line in wantedfile:
        if sentence.find(line.strip('\n')) >= 0:
            found.append(line.strip('\n'))
    return found

def saveKeyWords(array):
    for line in array:
        if line != '':
            keywordsfile.write(line + '\n')

saveKeyWords(searchKeyWords(commandStrip(instructionsfile.read())))

dotsfile.close()
wantedfile.close()
keywordsfile.close()
instructionsfile.close()