Why is the file saved showing None while console shows the correct response?

Question

When I try to save the responses to a file, the actual response is not saved even though it shows in the console. The result that is saved in the file is None. See examples below

from concurrent.futures import ThreadPoolExecutor
import requests
#from timer import timer


#########  create test file

URLsTest = '''
https://en.wikipedia.org/wiki/NBA
https://en.wikipedia.org/wiki/NFL
'''.strip()

with open('input.txt', 'w') as f:
    f.write(URLsTest)
    
####################

with open('input.txt', 'r') as f:
    urls=f.read().split('\n')    # url list

def fetch(tt):  # received tuple
    session, url = tt
    print('Processing')
    with session.get(url) as response:
        print(response.text)

#@timer(1, 5)
def main():
    with ThreadPoolExecutor(max_workers=100) as executor:
        with requests.Session() as session:  # for now, just one session
            results = executor.map(fetch, [(session, u) for u in urls])  # tuple list (session, url), each tuple passed to function
            executor.shutdown(wait=True)
    # write all results to text file
    with open('output.txt', 'w') as f2:
        for r in results:  # tuple (url, html)
            f2.write("%s\n" % r)
            
main()

Response file - output.txt

None    
None

Answer 1

First of all, you could avoid printing the html since you are saving that output to a file. That way you can avoid using resources to print the results.

Then, your fetch is not returning anything for the results. Therefore you should change your print for a return So instead of printing return the response.text

# print(response.text)
return response.text