How to get Telegram channel name from channel id using Telethon

I am trying to extract channel name or rest of channel details from channel ID.

I'm using the code as defined in Telethon's documentation:

api_id = #######
api_hash = ##################

client = TelegramClient(session_name, api_id, api_hash)
client.start()

channel_id1 = 1141171940
print(client.get_entity(PeerChannel(channel_id1)))

Now for this given channel ID, I'm getting the channel details!

However, for below channel ID:

channel_id2 = 1126629353
print(client.get_entity(PeerChannel(channel_id2)))

Code is not working.

Error:

ValueError: Could not find the input entity for PeerChannel(channel_id=1126629353) (PeerChannel). Please read https://docs.telethon.dev/en/stable/concepts/entities.html to find out more details.

Since, I already know this channel information. If I give channel name and then retrieve the channel details, there ID is exact same as provided above.

print(client.get_entity("https://t.me/kremlinprachka"))

Output (reduced): Channel(id=1126629353, title='Кремлёвская прачка')

can you please help me figure out what to do?

This is natural.

When you pass int id to get_entity or get_input_entity, Telethon needs to construct an InputPeerChannel (in your case), and pass it to the GetChannelsRequest, however, if you look at the parameters, it requires something called access_hash, those are received to your current session when Telegram feels like you need access to something. as attributes in User, Channel objects, from events or making other requests, for instance get_entity("username") will call ResolveUsernameRequest. deep within the attributes, it will contain a Channel obj, if you look hard enough at it, you will find an attribute called access_hash, what telethon does is, for every event you receive for every request you make and its response, it will store all the ids mapped to access hashes from those objects it finds to memory first, then to a .session file in working directory eventually for upcoming re-usage.

so, if you just switched your order in code, you'd see it working for next times...

  username = client.get_entity("https://t.me/kremlinprachka")
  print("With username:", username)
  # now it gets cached
  ids = username.id
  # now you can use the id for upcoming times, since access_hash was stored.
  print("With Id:", client.get_entity(PeerChannel(ids)))

Basics you must follow:

• Any integer id you pass to the library MUST be printed/stored from within the library through innumerable ways, id taken from anywhere else guarantees reaching a ValueError and no hash to be found internally.
• Do NOT delete the .session file.
• Call client.disconnect() properly to ensure export of memory cache safely.