all_user_details = []
for participant in all_participants:
    all_user_details.append(
        {"id": participant.id, "first_name": participant.first_name, "last_name": participant.last_name,
         "user": participant.username, "phone": participant.phone, "is_bot": participant.bot})

with open('user_data.json', 'w') as outfile:
    json.dump(all_user_details, outfile)