blockMessage = "MESSAGGIO DI BLOCCO QUI"

from telethon.tl.functions.contacts import BlockRequest

@register(outgoing=True, pattern="^[.]block$")
async def blockUser(e):
  if not (await e.get_sender()).bot:
    global blockMessage
    if e.is_reply:
      reply = await e.get_reply_message()
      await e.delete()
      await e.client.send_message(reply.chat_id, blockMessage, reply_to=reply)
      await e.client(BlockRequest(reply.sender.id))
    else:
      if e.is_private:
        await e.edit(blockMessage)
        await e.client(BlockRequest(e.chat_id))