delete all of the world that in a list from a txt file read with utf8

def delete_words(words, file):
    f = open(file, 'r', encoding='utf8')
    for line in f.readlines():
        for word in words:
            line = line.replace(word, '')
        f1 = open(file, 'a', encoding='utf8')
        f1.write(line)
    f.close()