Get info about Telagram chat participants using https://github.com/LonamiWebs/Telethon

telethon_get_participants_request.py

from telethon import TelegramClient
from telethon.tl.functions.channels import GetParticipantsRequest
from telethon.tl.types import ChannelParticipantsRecent
from telethon.utils import get_input_peer

api_id = 123456  # Use your own values here. https://my.telegram.org
api_hash = '0123456789abcdef0123456789abcdef'
phone_number = '+34600000000'

client = TelegramClient('%sessionname%', api_id, api_hash)  # feel free to edit %sessionname% as you want
client.connect() # logining and connecting to Telegram servers

if not client.is_user_authorized():  # authorization (if there is no .session file created before)
    client.send_code_request(phone_number)
    client.sign_in(phone_number, input('Enter the code: '))

# Using built-in methods
dialogs, entities = client.get_dialogs(count=10)  # getting info about first 10 chats

result = client.invoke(
    GetParticipantsRequest(get_input_peer(entities[6]),  # Getting 7th chat participants
                           filter=ChannelParticipantsRecent(),
                           # List of filters https://lonamiwebs.github.io/Telethon/types/channel_participants_filter.html
                           offset=0,  # getting info from 0th user
                           limit=5)  # limiting number of users in a request
)

info = result
print(info.users[3])  # prints info about 4th %filtered% Chat participant
# Example: (user (ID: 0xd10d979a) = (is_self=None, contact=None, mutual_contact=None, deleted=None, bot=None, bot_chat_history=None, bot_nochats=None, verified=None, restricted=None, min=None, bot_inline_geo=None, id=100761605, access_hash=-2961737078536444064, first_name=Pavel, last_name=Davydov, username=paveldavydov, phone=None, photo=(userProfilePhoto (ID: 0xd559d8c8) = (photo_id=432767798623709098, photo_small=(fileLocation (ID: 0x53d69076) = (dc_id=2, volume_id=710237640, local_id=19652, secret=******************(maybe there is really something secret, dunno))), photo_big=(fileLocation (ID: 0x53d69076) = (dc_id=2, volume_id=710237640, local_id=19654, secret=*******************)))), status=(userStatusOffline (ID: 0x8c703f) = (was_online=1494417103)), bot_info_version=None, restriction_reason=None, bot_inline_placeholder=None))
# Here is an id, access_hash, name and another info (that you might don't need)

code is based on outdated Telethon API -.-

@limsingrong

client(GetParticipantsRequest(peer, ChannelParticipantsRecent(), offset=offset, limit=200, hash=0))

I found that that hash argument should equal zero. Don't ask why - IDK ¯\_(ツ)_/¯