# Examples

This folder contains several single-file examples using [Telethon].

## Requisites

You should have the `telethon` library installed with `pip`.
Run `python3 -m pip install --upgrade telethon --user` if you don't
have it installed yet (this is the most portable way to install it).

The scripts will ask you for your API ID, hash, etc. through standard input.
You can also define the following environment variables to avoid doing so:

* `TG_API_ID`, this is your API ID from https://my.telegram.org.
* `TG_API_HASH`, this is your API hash from https://my.telegram.org.
* `TG_TOKEN`, this is your bot token from [@BotFather] for bot examples.
* `TG_SESSION`, this is the name of the `*.session` file to use.

## Downloading Examples

You may download all and run any example by typing in a terminal:
```sh
git clone https://github.com/LonamiWebs/Telethon.git
cd Telethon
cd telethon_examples
python3 gui.py
```

You can also right-click the title of any example and use "Save Link As…" to
download only a particular example.

All examples are licensed under the [CC0 License], so you can use
them as the base for your own code without worrying about copyright.

## Available Examples

### [`print_updates.py`]

* Usable as: **user and bot**.
* Difficulty: **easy**.

Trivial example that just prints all the updates Telegram originally
sends. Your terminal should support UTF-8, or Python may fail to print
some characters on screen.

### [`print_messages.py`]

* Usable as: **user and bot**.
* Difficulty: **easy**.

This example uses the different `@client.on` syntax to register event
handlers, and uses the `pattern=` variable to filter only some messages.

There are a lot other things you can do, but you should refer to the
documentation of [`events.NewMessage`] since this is only a simple example.

### [`replier.py`]

* Usable as: **user and bot**.
* Difficulty: **easy**.

This example showcases a third way to add event handlers (using decorators
but without the client; you should use the one you prefer) and will also
reply to some messages with different reactions, or to your commands.

It also shows how to enable `logging`, which you should always do, but was
not really needed for the previous two trivial examples.

### [`assistant.py`]

* Usable as a: **bot**.
* Difficulty: **medium**.

This example is the actual bot account [@TelethonianBot] running in the
[official Telethon's chat] to help people out. The file is a bit big and
assumes some [`asyncio`] knowledge, but otherwise is easy to follow.

In addition, it has optional plugins, which may be useful for your own code.
The plugins can be found at https://github.com/Lonami/TelethonianBotExt and
should be cloned into a `plugins` folder next to `assistant.py` for them to
work.

### [`interactive_telegram_client.py`]

* Usable as: **user**.
* Difficulty: **medium**.

Interactive terminal client that you can use to list your dialogs,
send messages, delete them, and download media. The code is a bit
long which may make it harder to follow, and requires saving some
state in order for downloads to work later.

### [`quart_login.py`]

* Usable as: **user**.
* Difficulty: **medium**.

Web-based application using [Quart](https://pgjones.gitlab.io/quart/index.html)
(an `asyncio` alternative to [Flask](http://flask.pocoo.org/)) and Telethon
together.

The example should work as a base for Quart applications *with a single
global client*, and it should be easy to adapt for multiple clients by
following the comments in the code.

It showcases how to login manually (ask for phone, code, and login),
and once the user is logged in, some messages and photos will be shown
in the page.

There is nothing special about Quart. It was chosen because it's a
drop-in replacement for Flask, the most popular option for web-apps.
You can use any `asyncio` library with Telethon just as well,
like [Sanic](https://sanic.readthedocs.io/en/latest/index.html) or
[aiohttp](https://docs.aiohttp.org/en/stable/). You can even use Flask,
if you learn how to use `threading` and `asyncio` together.

### [`gui.py`]

* Usable as: **user and bot**.
* Difficulty: **high**.

This is a simple GUI written with [`tkinter`] which becomes more complicated
when there's a need to use [`asyncio`] (although it's only a bit of additional
setup). The code to deal with the interface and the commands the GUI supports
also complicate the code further and require knowledge and careful reading.

This example is the actual bot account [@TelethonianBot] running in the
[official Telethon's chat] to help people out. The file is a bit big and
assumes some [`asyncio`] knowledge, but otherwise is easy to follow.

![Screenshot of the tkinter GUI][tkinter GUI]


[Telethon]: https://github.com/LonamiWebs/Telethon
[CC0 License]: https://github.com/LonamiWebs/Telethon/blob/master/telethon_examples/LICENSE
[@BotFather]: https://t.me/BotFather
[`assistant.py`]: https://raw.githubusercontent.com/LonamiWebs/Telethon/master/telethon_examples/assistant.py
[`quart_login.py`]: https://raw.githubusercontent.com/LonamiWebs/Telethon/master/telethon_examples/quart_login.py
[`gui.py`]: https://raw.githubusercontent.com/LonamiWebs/Telethon/master/telethon_examples/gui.py
[`interactive_telegram_client.py`]: https://raw.githubusercontent.com/LonamiWebs/Telethon/master/telethon_examples/interactive_telegram_client.py
[`print_messages.py`]: https://raw.githubusercontent.com/LonamiWebs/Telethon/master/telethon_examples/print_messages.py
[`print_updates.py`]: https://raw.githubusercontent.com/LonamiWebs/Telethon/master/telethon_examples/print_updates.py
[`replier.py`]: https://raw.githubusercontent.com/LonamiWebs/Telethon/master/telethon_examples/replier.py
[@TelethonianBot]: https://t.me/TelethonianBot
[official Telethon's chat]: https://t.me/TelethonChat
[`asyncio`]: https://docs.python.org/3/library/asyncio.html
[`tkinter`]: https://docs.python.org/3/library/tkinter.html
[tkinter GUI]: https://raw.githubusercontent.com/LonamiWebs/Telethon/master/telethon_examples/screenshot-gui.jpg
[`events.NewMessage`]: https://docs.telethon.dev/en/latest/modules/events.html#telethon.events.newmessage.NewMessage