import requests
from urllib.request import urlopen
from bs4 import BeautifulSoup

for i in range(2):      # Number of pages plus one
    url = "https://example.com/".format(i)
    r = requests.get(url)

try:
   page = urlopen(url)
except:
   print("Error opening the URL")

soup = BeautifulSoup(page, 'html.parser')
user = soup.find_all('span', {"class" : 'users'})
user = soup.find_all ('users[0]')
with open('output.txt', 'a', encoding='utf-8') as f_out:
    f_out.write(str(user))
    f_out.close()