main.py

import logging
import os

from dotenv import load_dotenv

from telegram import Update
from telegram.ext import ApplicationBuilder, CommandHandler, ContextTypes, MessageHandler, filters

# Enable logging
logging.basicConfig(
    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s", level=logging.INFO
)

load_dotenv()  # take environment variables from .env.

TELEGRAM_TOKEN = os.getenv('TELEGRAM_TOKEN')


async def start(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
    await update.message.reply_text(f'Start {update.effective_user.first_name}')


async def hello(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
    await update.message.reply_text(f'Hello {update.effective_user.first_name}')


async def echo(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
    message = update.message.text.lower()

    if 'привіт' in message:
        reply_text = f'Привіт {update.effective_user.first_name}!'
    else:
        reply_text = 'Я тебе не розумію.'

    await update.message.reply_text(reply_text)

app = ApplicationBuilder().token(TELEGRAM_TOKEN).build()

app.add_handler(CommandHandler("start", start))
app.add_handler(CommandHandler("hello", hello))
app.add_handler(MessageHandler(filters.TEXT & ~filters.COMMAND, echo))

app.run_polling()