Twitter Handle retriever by User ID. For u/mahonmadasulah. https://www.reddit.com/r/programmingrequests/comments/altr67/request_convert_list_of_twitter_user_ids_into/

get_users.py

# You should have a .txt file named users.txt in the same directory you run this script in. 
# You will need to have install beautifulsoup4 as well as rquest

from bs4 import BeautifulSoup as bs
import requests
import csv

twitter_ids = []
twitter_handles = {}

user_file =  open('users.txt', 'r')
for id in user_file:
    # dont get empty lines from .txt file and strip the newline character
    if id != '\n':
        twitter_ids.append(id.strip('\n'))

for id in twitter_ids:
    print("Fetching @Handle for ID %s" % id)
    url = "http://www.twitter.com/intent/user?user_id=%s" % id
    result = requests.get(url)
    
    if result.status_code == requests.codes.not_found:
        print("ID %s returned a 404.\n" % id)
        continue
        
    soup = bs(result.content, 'html.parser')
    handle_element = soup.find_all('span', {'class':'nickname'})
    if len(handle_element) > 0:
        handle = handle_element[0].text
        twitter_handles[id] = handle
        print("ID %s is %s\n" % (id, handle)) 
    else:
        print("Couldnt Find a handle for ID %s. User is either suspended or invalid.\n" % id)

total_handles = len(twitter_handles.keys())
total_ids = len(twitter_ids)
print("A Total of %d were found out of %d IDs" % (total_handles, total_ids))

with open("output.csv", "wb") as f:
    writer = csv.writer(f)
    for uid in twitter_handles.keys():   
        writer.writerow([uid, twitter_handles[uid]])

users.txt

15826896
14785236
14787878
78547820
00000000
00000014
00004444
88888888
19191919
00000000