Develop Reference

Incoming Telegram message listener with Telethon

I'd like to listen for a new incoming message in a Telegram channel.
I'm using the Telethon package and tried to run the example found in the docs.
from telethon import TelegramClient, events
api_id = "..."
api_hash = "..."
CHANNEL_ID = "..."
client = TelegramClient('anon', api_id, api_hash)
client.start()
#client.on(events.NewMessage(chats=CHANNEL_ID, outgoing=False))
async def my_event_handler(event):
print(event)
client.run_until_disconnected()
This code runs, asks me for my phone number and the login code. But after that, nothing happens.
When a message is sent to the channel, I don't see anything printed out.

Bot does not send media telethon

I'm making a bot that displays new messages from different chats to the user. The first client, acting as a user, listens to the channels, and the second client, acting as a bot, displays a new message to the user.
from telethon import TelegramClient, events
api_id = '...'
api_hash = '...'
bot_token = '...'
client = TelegramClient('client', api_id, api_hash)
bot = TelegramClient('bot', api_id, api_hash).start(bot_token=bot_token)
client.start()
#client.on(events.NewMessage(chats=['...']))
async def main(event):
await bot.send_message('...', event.message)
client.run_until_disconnected()
But there is a problem: if media appears in the message, then the bot does not send the message and displays the following error:
telethon.errors.rpcerrorlist.MediaEmptyError: The provided media object is invalid or the current account may not be able to send it (such as games as users) (caused by SendMediaRequest)
If the message is sent by the first client, then the message is sent and no error occurs.
Help me please!

python telethon wait for reply

I currently have code to send message to my friend
but how can I know if he reply
this is my current code
please see the commented line
from telethon import TelegramClient
api_id = '1234567'
api_hash = 'MYHASH'
client = TelegramClient('session', api_id, api_hash)
client.start(phone_number)
destination_user_username='friend'
entity=client.get_entity(destination_user_username)
client.send_message(entity=entity,message="hello")
#if he reply hi
client.send_message(entity=entity,message="have a nice day")
how can I do this?

I found in the doc
solution 1
for message in client.iter_messages(chat):
print(message)
solution 2
api_id = '1234567'
api_hash = 'MYHASH'
with TelegramClient('session') as client:
destination_user_username='friend'
entity=client.get_entity(destination_user_username)
client.send_message(entity=entity,message="hello")
from telethon import events
#client.on(events.NewMessage(pattern='hi'))
async def handler(event):
# here received messgae, do something with event
print(dir(event)) # check all possible methods/operations/attributes
# reply once and then disconnect
await event.reply("have a nice day")
await client.disconnect()
client.run_until_disconnected()

How to get a Telegram bot about or description using telethon

When I get the history chat message with a bot I can't see the "hello" message ("What can this bot do?") in the return message_context. How can I get it?
message_context = client.send_message(bot_name, '/start')
for message in client.iter_messages(bot_name):
print("{}".format(bot_name))

You need to use GetFullUserRequest to fetch the bot_info attribute of the UserFull instance:
from telethon.sync import TelegramClient
from telethon import functions, types
with TelegramClient(name, api_id, api_hash) as client:
result = client(functions.users.GetFullUserRequest(bot_name))
bot_info = result.bot_info
print(bot_info)
print(bot_info.description)

Telegram get chat messages /posts - python Telethon

I am using Telethon and Python 3.6xx
Been able to retreive message from groups, no problem but when it comes to channels I am stuck.
dialogs = client(get_dialogs)
for chat in dialogs.chats:
getmessage = client.get_messages(chat.id, limit=400)
for message in getmessage:
print(message.message)
I've searched the telethon documentation but most answers were in response to the old get_message_history.
When I'm trying with the following chat.id = 1097988869 (news.bitcoin.com) I'm getting an error below (for groups the chat.id works fine):
PeerIdInvalidError: An invalid Peer was used. Make sure to pass the right peer type

The accepted answer is good, but recent versions of Telethon let you achieve the same more easily. This will iterate over all messages in chat (for this example we use telethon.sync to avoid typing out async):
from telethon.sync import TelegramClient
with TelegramClient(name, api_id, api_hash) as client:
for message in client.iter_messages(chat):
print(message.sender_id, ':', message.text)
Where the variables should be obvious, for example (note these API values won't work, you need your own):
name = 'anon'
api_id = 123
api_hash = 'abcdefgh'
chat = 'me'
More examples using async are available in client.iter_messages documentation.

update :
in the new version of Telethon, #Lonami answer is best and use it.
############################################################
you can use this code for get messages :
client = TelegramClient('session_name',
api_id,
api_hash,
update_workers=1,
spawn_read_thread=False)
assert client.connect()
if not client.is_user_authorized():
client.send_code_request(phone_number)
me = client.sign_in(phone_number, input('Enter code: '))
channel_username='tehrandb' # your channel
channel_entity=client.get_entity(channel_username)
posts = client(GetHistoryRequest(
peer=channel_entity,
limit=100,
offset_date=None,
offset_id=0,
max_id=0,
min_id=0,
add_offset=0,
hash=0))
# messages stored in `posts.messages`

that work for me!
api_hash from https://my.telegram.org, under API Development.
from telethon import TelegramClient, events, sync
api_id = 'your api_id'
api_hash = 'your api_hash'
client = TelegramClient('session_name', api_id, api_hash)
client.start()
channel_username = 'username'# your channel
for message in client.get_messages(channel_username, limit=10):
print(message.message)