groups.py

from telethon.tl.functions.messages import GetDialogsRequest
from telethon.tl.types import InputPeerEmpty
import csv
import details as ds

#Login details#
api_id = ds.apiID
api_hash = ds.apiHash
phone = ds.number
client = TelegramClient(phone, api_id, api_hash)

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

chats = []
last_date = None
chunk_size = 200
groups=[]

result = client(GetDialogsRequest(
             offset_date=last_date,
             offset_id=0,
             offset_peer=InputPeerEmpty(),
             limit=chunk_size,
             hash = 0
         ))
chats.extend(result.chats)

for chat in chats:
    try:
        if chat.megagroup== True:
            groups.append(chat)
    except:
        continue

print('Choose a group to scrape members from:')
i=0
for g in groups:
    print(str(i) + '- ' + g.title)
    i+=1

g_index = input("Enter a Number: ")
target_group=groups[int(g_index)]

print('Fetching members...')
all_participants = []
all_participants = client.get_participants(target_group, aggressive=True)

print('Creating file...')
file_name = ""+str(target_group.title)+"_members.csv"

print('Saving in file...')
with open(file_name,"w",encoding='UTF-8') as f:
    writer = csv.writer(f,delimiter=",",lineterminator="\n")
    writer.writerow(['username','user id','name','group', 'group id'])
    for user in all_participants:
        if user.username:
            username= user.username
        else:
            username= ""
        if user.first_name:
            first_name= user.first_name
        else:
            first_name= ""
        if user.last_name:
            last_name= user.last_name
        else:
            last_name= ""
        name= (first_name + ' ' + last_name).strip()
        writer.writerow([username,user.id,name,target_group.title, target_group.id])
print('Members scraped successfully.')

again = input('Do you want to scrape more groups? (y/n)')
if again == 'y':
    print('Restarting...')
    exec(open("groups.py").read())
else:
    pass

launcher = input('Do you want to return to the launcher? (y/n)')
if launcher == 'y':
    print('Restarting...')
    exec(open("launcher.py").read())
else:
    print('Thank you for using the Telegram scraper.')