How to get all users in a telegram channel using telethon?

Question

I'm new to telethon and python. I have installed telethon in python3 and I want to get all members of a telegram channel or a group . I was searching a lot in the internet and found below code . And I'm trying really hard to understand it .Telegram documentation is not enough to do this . Is there a better solution ?

from telethon import TelegramClient

from telethon.tl.functions.contacts import ResolveUsernameRequest
from telethon.tl.functions.channels import GetAdminLogRequest
from telethon.tl.functions.channels import GetParticipantsRequest

from telethon.tl.types import ChannelParticipantsRecent
from telethon.tl.types import InputChannel
from telethon.tl.types import ChannelAdminLogEventsFilter
from telethon.tl.types import InputUserSelf
from telethon.tl.types import InputUser
# These example values won't work. You must get your own api_id and
# api_hash from https://my.telegram.org, under API Development.
api_id = 12345
api_hash = '8710a45f0f81d383qwertyuiop'
phone_number = '+123456789'

client = TelegramClient(phone_number, api_id, api_hash)





client.session.report_errors = False
client.connect()

if not client.is_user_authorized():
    client.send_code_request(phone_number)
    client.sign_in(phone_number, input('Enter the code: '))

channel = client(ResolveUsernameRequest('channelusername')) # Your channel username

user = client(ResolveUsernameRequest('admin')) # Your channel admin username
admins = [InputUserSelf(), InputUser(user.users[0].id, user.users[0].access_hash)] # admins
admins = [] # No need admins for join and leave and invite filters

filter = None # All events
filter = ChannelAdminLogEventsFilter(True, False, False, False, True, True, True, True, True, True, True, True, True, True)
cont = 0
list = [0,100,200,300]
for num in list:
    result = client(GetParticipantsRequest(InputChannel(channel.chats[0].id, channel.chats[0].access_hash), filter, num, 100))
    for _user in result.users:
        print( str(_user.id) + ';' + str(_user.username) + ';' + str(_user.first_name) + ';' + str(_user.last_name) )
with open(''.join(['users/', str(_user.id)]), 'w') as f: f.write(str(_user.id))

But I'm getting this error . What have I missed ?

Traceback (most recent call last):
  File "run.py", line 51, in <module>
    result = client(GetParticipantsRequest(InputChannel(channel.chats[0].id, channel.chats[0].access_hash), filter, num, 100))
TypeError: __init__() missing 1 required positional argument: 'hash'

Answer 1

Sean answer won't make any difference.

Your code works for older Telethon versions. In the new versions, a new argument hash is added to GetParticipantsRequest method. Therefore, you need to pass hash as an argument too. Add hash=0 like this:

result = client(GetParticipantsRequest(InputChannel(channel.chats[0].id, channel.chats[0].access_hash), filter, num, 100, 0))

Note that the hash of the request is not the channel hash. It's a special hash calculated based on the participants you already know about, so Telegram can avoid resending the whole thing. You can just leave it to 0.

Here is an up-to-date example from official Telethon wiki.

Answer 2

I think You can use this code in the new version of Telethon

from telethon import TelegramClient
from telethon.tl.functions.channels import GetParticipantsRequest
from telethon.tl.functions.channels import GetFullChannelRequest
from telethon.tl.types import ChannelParticipantsSearch

api_id = XXXXX
api_hash = 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'
phone_number = '+98XXXXXXXX'
################################################
channel_username = 'tehrandb'
################################################

client = TelegramClient('session_name',api_id,api_hash)

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

# ---------------------------------------
offset = 0
limit = 200
my_filter = ChannelParticipantsSearch('')
all_participants = []
while_condition = True
# ---------------------------------------
channel = client(GetFullChannelRequest(channel_username))
while while_condition:
    participants = client(GetParticipantsRequest(channel=channel_username, filter=my_filter, offset=offset, limit=limit, hash=0))
    all_participants.extend(participants.users)
    offset += len(participants.users)
    if len(participants.users) < limit:
         while_condition = False

I used ‍Telethon V0.19, but the previous versions are pretty much the same