def check(update, context):
if update.message.new_chat_members:
for new_member in update.message.new_chat_members:
if new_member.username == bot_name:
return start(update, context)
else:
return welcome(update, context, new_member)
def welcoming_task(message):
if not validate_command(message, check_chat=True):
return
welcome.welcome(message)