Developing a Telegram Bot in Python
Egor
Developing a Telegram Bot Using the Python-telegram-bot Library
Telegram bots are becoming increasingly popular due to their functionality and ease of use. In this article, we will go through how to create a simple Telegram bot using the python-telegram-bot library.
First, you need to create a virtual environment:
python3 -m venv .venv
.venv\Scripts\activate # for Windows.
.venv/bin/activate # for Linux systems.Then install the python-telegram-bot library using pip:
pip install python-telegram-botTo create a bot in Telegram:
Open Telegram and search for the bot @BotFather. Send the command /newbot and follow the instructions to create a
new bot. After creating your bot, you will receive a token that will be used to interact with the Telegram API.
Handlers
Commands
Now that we have a token, we can start writing the code. Create a file named bot.py and add the following code:
from telegram import Update
from telegram.ext import Application, CommandHandler, ContextTypes
# Function to be called when the /start command is issued
async def start(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
await update.message.reply_text("Hello! I'm your Telegram bot.")
# Main function to run the bot
def main() -> None:
# Insert your token here
app = Application.builder().token("YOUR_TOKEN_HERE").build()
# Register the handler
app.add_handler(CommandHandler("start", start))
# Start the bot
app.run_polling()
if __name__ == "__main__":
main()Replace YOUR_TOKEN_HERE with the token provided by BotFather. Then, run your bot:
python3 bot.pyNow your bot will be up and running and will respond to the /start command.
Adding New Commands
You can easily extend your bot’s functionality by adding new commands. For example, let’s add a /help command that
displays a list of available commands:
from telegram import Update
from telegram.ext import Application, CommandHandler, ContextTypes
# Function to be called when the /start command is issued
async def start(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
await update.message.reply_text("Hello! I'm your Telegram bot.")
# New function for the /help command
async def help(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
await update.message.reply_text(
"""
List of commands:
/start - Greeting message.
/help - Help.
"""
)
def main() -> None:
app = Application.builder().token("YOUR_TOKEN_HERE").build()
app.add_handler(CommandHandler("start", start))
# Register the new handler
app.add_handler(CommandHandler("help", help))
# Start the bot
app.run_polling()
if __name__ == "__main__":
main()Text Messages
You can also handle text messages sent by users. To do this, add the following handler:
from telegram import Update
from telegram.ext import Application, MessageHandler, ContextTypes, filters
async def echo(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
await update.message.reply_text(update.message.text)
def main() -> None:
app = Application.builder().token("YOUR_TOKEN_HERE").build()
# Register the handler
app.add_handler(MessageHandler(filters.TEXT, echo))
# Start the bot
app.run_polling()
if __name__ == "__main__":
main()This code will duplicate any text messages received from the user.
There are many handlers available, but the most commonly used ones are MessageHandler and CommandHandler, as demonstrated above.
Also, the filters object allows you to handle all sorts of messages in the chat, whether text, photos, videos, etc. For a better understanding, I recommend checking out the documentation.
