Test

gistfile1.txt

from telethon import TelegramClient
import pandas as pd
import asyncio

api_id = ...
api_hash = '...'
phone = '+7...'
channel_href = 'https://t.me/...'

async def start():
    client = TelegramClient('session_name', api_id, api_hash)
    client = await client.start()
    dialogs = await client.get_dialogs()

async def then():
    channels = {d.entity.username: d.entity
        for d in dialogs
        if d.is_channel}
    my_channel = channel_href.split('/')[-1]
    channel = channels[my_channel]

async def get():
    members_telethon_list = await client.get_participants(channel, aggressive=True)

async def next():
    username_list = [member.username for member in members_telethon_list]
    first_name_list = [member.first_name for member in members_telethon_list]
    last_name_list = [member.last_name for member in members_telethon_list]
    phone_list = [member.phone for member in members_telethon_list]

async def last():
    df = pd.DataFrame()
    df['username'] = username_list
    df['first_name'] = first_name_list
    df['last_name'] = last_name_list
    df['phone'] = phone_list
    df.to_csv('subscribers.csv', index=False)