from telethon import TelegramClient, sync

# Use your own values here
api_id = '123456'
api_hash = 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxx'
channel = 'channel_name'

client = TelegramClient('Session_details', api_id, api_hash)
phone_number='9199999999'

client.connect()
print("Connected")
if not client.is_user_authorized():
    client.send_code_request(phone_number)
    me = client.sign_in(phone_number, input('Enter code: '))


# get all the users and print them
for u in client.iter_participants(channel, aggressive=True):
  print(u.id, u.first_name)


client.disconnect()
print("Disconnected")