Completely deleting duplicates words in a text file

I have some words in a text file like:

joynal
abedin
rahim
mohammad
joynal
abedin 
mohammad
kudds

I want to delete the duplicate names. It will delete these duplicate entries totally from the text file

The output should be like:

rahim 
kuddus

I have tried some coding but it’s only giving me the duplicate values as one like 1.joynal and 2.abedin.

Edited: This is the code I tried:

content = open('file.txt' , 'r').readlines()
content_set = set(content)
cleandata = open('data.txt' , 'w')

for line in content_set:
    cleandata.write(line)

>Solution :

Use a Counter:

from collections import Counter 

with open(fn) as f:
    cntr=Counter(w.strip() for w in f)

Then just print the words with a count of 1:

>>> print('\n'.join(w for w,cnt in cntr.items() if cnt==1))
rahim
kudds

Or do it the ‘old fashion way’ with a dict as a counter:

cntr={}
with open(fn) as f:
    for line in f:
        k=line.strip()
        cntr[k]=cntr.get(k, 0)+1

>>> print('\n'.join(w for w,cnt in cntr.items() if cnt==1))
# same

If you want to output to a new file:

with open(new_file, 'w') as f_out:
    f_out.write('\n'.join(w for w,cnt in cntr.items() if cnt==1))