[Python] Edit a telegram bot message dynamically when using stream=True in...

I'm developing a telegram bot using aiogram which takes user's message as a prompt and generates a response using google-generativeai GenerativeModel. It works fine in normal mode, where I wait for a complete response, but I want to yield chunks of response with the stream=True parameter and add new chunks to a telegram message with message.edit_text() function. The problem is that I'm encountering an error: aiogram.exceptions.TelegramBadRequest: Telegram server says - Bad Request: can't parse entities: Can't find end of the entity starting at byte offset 73

Here are my functions:

from aiogram import Bot, Dispatcher, Router, types
from aiogram.client.default import DefaultBotProperties
from aiogram.enums import ParseMode
from google.api_core.exceptions import BadRequest as GoogleBadRequest

from app.database import engine
from app.models import Language, TelegramUser
from app.services.ai import generate_response
from app.services.users import get_or_create_telegram_user, get_translated_message as _, refresh_last_interaction_date


bot = Bot(token=TOKEN,
default=DefaultBotProperties())

dp = Dispatcher()

telegram_router = Router()

dp.include_router(telegram_router)

...

@dp.message()
async def handle_prompt(message: types.Message):
async with AsyncSession(engine) as db:
user, __ = await get_or_create_telegram_user(message, db)
prompt = message.text

temp_message_text = await _("timer_1", user.language_id, db)
temp_message = await message.answer(temp_message_text)

# Accumulate the complete response
accumulated_text = ""

try:
async for chunk in generate_response(prompt):
accumulated_text += chunk

# Send the complete response with correct formatting
await temp_message.edit_text(
accumulated_text,
disable_web_page_preview=True,
parse_mode=ParseMode.MARKDOWN
)

except Exception as e:
print(f"Error in handle_prompt: {e}")
await temp_message.edit_text("An error occurred during processing.")

finally:
await refresh_last_interaction_date(user.chat_id, db)


# ai.py

from typing import AsyncGenerator

import google.generativeai as genai

from app.constants import GEMINI_API_KEY
from app.utils.helpers import sync_to_async_iterable

# Set up the Gemini API configuration
genai.configure(api_key=GEMINI_API_KEY)

# Initialize the Gemini model
model = genai.GenerativeModel(model_name="gemini-1.5-flash")


async def generate_response(prompt: str, **kwargs) -> AsyncGenerator[str, None]:
try:
response = sync_to_async_iterable(model.generate_content(prompt, stream=True, **kwargs))
async for content in response:
yield content.text
except Exception as e:
print(f"Error in generate_response: {e}")
yield "An error occurred during processing." # Yield an error message


The problem is that when I get chunks of the response, sometimes a markdown opening symbol is present in the chunk, but the closing symbol is not. If this happens, the error aiogram.exceptions.TelegramBadRequest: Telegram server says - Bad Request: can't parse entities: Can't find end of the entity starting at byte offset .. occurs. I've tried both ParseMode.MARKDOWN and ParseMode.MARKDOWN_V2, but the problem is the same. I've tried to remove parse_mode parameter if this exception is raised, but it didn't seem to help.

I've found out that generate_contents() returns a text formatted with markdown2 and that Telegram requires strict formatting.

I'm not very familiar with markdown formatting and asynchronous programming and I need help with this problem.

Python version: 3.10.8
Packages used:

aiogram==3.15.0
google-generativeai==0.8.3

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