How to use file.seek() inside a python loop?

Solution for How to use file.seek() inside a python loop?
is Given Below:

below is my simple code snippet where I want the program to read the file from the top again, in case a function is pleased:

wordlist = open('wordlist.txt', 'r')
words = wordlist.read().splitlines()
for word in words:
    if ...():
        wordlist.seek(0) #starting reading the file from the top again
        words = wordlist.read().splitlines()
        for word in words:
            if ...():
               #do sth else and so on

Any idea how to use file.seek() correctly, because when executed, the program continues to read the wordlist without going again to the start.