The "telethon" library has a "get messages" method, with which you can get a message and information about it, including comments.
But can you get reactions? https://core.telegram.org/method/messages.getMessageReactionsList
I couldn't find a way to do this via telethon. However, you can get a list of reactions to messages using pyrogram: GetMessageReactionsList
Something like that:
from pyrogram import Client
from pyrogram.raw.functions.messages import GetMessageReactionsList
app = Client(
"my_account",
api_id=12345678,
api_hash='XXX'
)
chat_id = -123456789
with app:
peer = app.resolve_peer(chat_id)
for message in app.iter_history(chat_id=chat_id):
reactions = app.send(
GetMessageReactionsList(
peer=peer,
id=message.message_id,
limit=100
)
)
UPD Found an easier way:
with app:
peer = app.resolve_peer(chat_id)
for message in app.iter_history(chat_id=chat_id):
print(message.reactions)