Telethon ======== .. epigraph:: ⭐️ Thanks **everyone** who has starred the project, it means a lot! **Telethon** is Telegram client implementation in **Python** which uses the latest available API of Telegram. Before opening an issue about how to use the library, **please** make sure you have read and followed the steps mentioned under `Using Telethon`_ and are using the latest version! A lot of people ask simple questions which will only be answered as "please see the ``README.rst``". And you should use the search before posting an issue, too. If you come here often, you may want to go to the `docs `_. .. contents:: Table of contents Why Telethon? ============= .. epigraph:: Why should I bother with Telethon? There are more mature projects already, such as `telegram-cli `_ with even (limited) Python support. And we have the `official `_ `clients `_! With Telethon you don't really need to know anything before using it. Create a client with your settings. Connect. You're ready to go. Being written **entirely** on Python, Telethon can run as a script under any environment you wish, (yes, `Android too `_). You can schedule it, or use it in any other script you have. Want to send a message to someone when you're available? Write a script. Do you want check for new messages at a given time and find relevant ones? Write a script. Hungry for more API calls which the ``TelegramClient`` class doesn't *seem* to have implemented? Please read `Using more than just TelegramClient`_. Obtaining your Telegram ``API ID`` and ``Hash`` =============================================== In order to use Telethon, you first need to obtain your very own API ID and Hash: 1. Follow `this link `_ and login with your phone number. 2. Click under *API Development tools*. 3. A *Create new application* window will appear. Fill in your application details. There is no need to enter any *URL*, and only the first two fields (*App title* and *Short name*) can be changed later as far as I'm aware. 4. Click on *Create application* at the end. Now that you know your ``API ID`` and ``Hash``, you can continue installing Telethon. Installing Telethon =================== Installing Telethon via ``pip`` ------------------------------- On a terminal, issue the following command: .. code:: sh sudo -H pip install telethon If you get something like "SyntaxError: invalid syntax" on the ``from error`` line, it's because ``pip`` defaults to Python 2. Use `pip3` instead. If you already have Telethon installed, upgrade with ``pip install --upgrade telethon``! Installing Telethon manually ---------------------------- 1. Install the required ``pyaes`` and ``rsa`` modules: ``sudo -H pip install pyaes rsa`` (`GitHub `_, `package index `_) 2. Clone Telethon's GitHub repository: ``git clone https://github.com/LonamiWebs/Telethon.git`` 3. Enter the cloned repository: ``cd Telethon`` 4. Run the code generator: ``python3 setup.py gen_tl`` 5. Done! To speed up the crypto part of Telethon, you should also install ``sympy`` and ``libssl`` on your computer. This step is optional. Running Telethon ================ If you've installed Telethon via pip, launch an interactive python3 session and enter the following: .. code:: python >>> from telethon import TelegramClient >>> api_id = 12345 >>> api_hash = '0123456789abcdef0123456789abcdef' >>> # 'session_id' can be 'your_name'. It'll be saved as your_name.session ... client = TelegramClient('session_id', api_id, api_hash) >>> client.connect() True >>> >>> if not client.is_user_authorized(): >>> client.send_code_request('+34600000000') >>> client.sign_in('+34600000000', input('Enter code: ')) ... >>> # Now you can use the connected client as you wish >>> dialogs, entities = client.get_dialogs(10) >>> print('\n'.join('{}. {}'.format(i, str(e)) ... for i, e in enumerate(entities))) If, on the other hand, you've installed Telethon manually, head to the ``api/`` directory and create a copy of the ``settings_example`` file, naming it ``settings`` (lowercase!). Then fill the file with the corresponding values (your ``api_id``, ``api_hash`` and phone number in international format). Then, simply run ``./try_telethon.py`` to start the interactive example. .. _Using Telethon: Using Telethon ============== If you really want to learn how to use Telethon, it is **highly advised** that you take a look to the `InteractiveTelegramClient `_ file and check how it works. This file contains everything you'll need to build your own application, since it shows, among other things: 1. Authorizing the user for the first time. 2. Support to enter the 2-steps-verification code. 3. Retrieving dialogs (chats) and the messages history. 4. Sending messages and files. 5. Downloading files. 6. Updates thread. If you want a nicer way to see all the available requests and types at your disposal, please check the `official Telethon documentation `_. There you'll find a list of all the methods, types and available constructors. More examples are also available under the ``telethon_examples/`` folder. If you're using Telethon under ARM, you may want to install ``sympy`` through ``pip`` for a substantial speed-up when generating the keys required to connect to Telegram (you can of course do this on desktop too). See `issue #199 `_ for more. Common errors ------------- Errors resulting from Telegram queries all subclass the ``RPCError`` class. This class is further specialized into further errors: * ``InvalidDCError`` (303), the request must be repeated on another DC. * ``BadRequestError`` (400), the request contained errors. * ``UnauthorizedError`` (401), the user is not authorized yet. * ``ForbiddenError`` (403), privacy violation error. * ``NotFoundError`` (404), make sure you're invoking ``Request``'s! * ``FloodError`` (420), the same request was repeated many times. Must wait ``.seconds``. * ``CdnFileTamperedError``, if the media you were trying to download has been altered. Further specialization is also available, for instance, the ``SessionPasswordNeededError`` when signing in means that a password must be provided to continue. If the error is not recognised, it will only be an ``RPCError``. Unless you know what you're doing, you should download media by always using the ``.download_file()`` function, which supports a ``str`` or a file handle as parameters. Otherwise, ``.invoke()`` may raise ``InvalidDCError`` which you will have to handle, and in turn call ``.invoke_on_dc()`` manually. Advanced uses ============= .. _Using more than just TelegramClient: Using more than just ``TelegramClient`` --------------------------------------- The ``TelegramClient`` class should be used to provide a quick, well-documented and simplified starting point. It is **not** meant to be a place for *all* the available Telegram ``Request``'s, because there are simply too many. However, this doesn't mean that you cannot ``invoke`` all the power of Telegram's API. Whenever you need to ``call`` a Telegram ``Request``, all you need to do is the following: .. code:: python result = client(SomeRequest(...)) # Or the old way: result = client.invoke(SomeRequest(...)) You have just called ``SomeRequest`` and retrieved its ``result``! That wasn't hard at all, was it? Now you may wonder, what's the deal with *all the power of Telegram's API*? Have a look under ``tl/functions/``. That is *everything* you can do. You have **over 200 API** ``Request``'s at your disposal. However, we don't pretty know *how* that ``result`` looks like. Easy. ``print(str(result))`` should give you a quick overview. Nevertheless, there may be more than a single ``result``! Let's have a look at this seemingly innocent ``TL`` definition: ``messages.getWebPagePreview#25223e24 message:string = MessageMedia;`` Focusing on the end, we can see that the ``result`` of invoking ``GetWebPagePreviewRequest`` is ``MessageMedia``. But how can ``MessageMedia`` exactly look like? It's time to have another look, but this time under ``tl/types/``: .. code:: sh $ tree -P "message_media_*" . ├── tl │   └── types │   ├── message_media_contact.py │   ├── message_media_document.py │   ├── message_media_empty.py │   ├── message_media_geo.py │   ├── message_media_photo.py │   ├── message_media_unsupported.py │   ├── message_media_venue.py │   └── message_media_web_page.py Those are *eight* different types! How do we know what exact type it is to determine its properties? A simple ``if type(result) == MessageMediaContact:`` or similar will do. Now you're ready to take advantage of Telegram's polymorphism. Tips for porting Telethon ------------------------- First of all, you need to understand how the ``scheme.tl`` (``TL`` language) works. Every object definition is written as follows: ``name#id argument_name:argument_type = CommonType`` This means that in a single line you know what the ``TLObject`` name is. You know it's unique ID, and you know what arguments it has. It really isn't that hard to write a generator for generating code to any platform! The generated code should also be able to *encode* the ``Request`` into bytes, so they can be sent over the network. This isn't a big deal either, because you know how the ``TLObject``'s are made. Once you have your own `code generator `_, start by looking at the `first release `_ of Telethon. The code there is simple to understand, easy to read and hence easy to port. No extra useless features. Only the bare bones. Perfect for starting a *new implementation*. P.S.: I may have lied a bit. The ``TL`` language is not that easy. But it's not that hard either. You're free to sniff the ``parser/`` files and learn how to parse other more complex lines. Or simply use that code and change the `SourceBuilder `_! Notes about the code generator ------------------------------ The code generator will skip the types considered as *core types*. These types are usually included in almost every programming language, such as boolean values or lists, and also the Telegram True flag, which is *not* sent but rather used to determine whether that flag should be enabled or not. Updating the ``scheme.tl`` -------------------------- Have you found a more updated version of the ``scheme.tl`` file? Those are great news! Updating is as simple as grabbing the `latest version `_ and replacing the one you can find in this same directory by the updated one. Don't forget to run ``python3 setup.py gen_tl``. If the changes weren't too big, everything should still work the same way as it did before; but with extra features. Using a proxy ------------- If you want to use Telethon via proxy, you have to install `PySocks (via pip or manual) `_. Once this is done, pass the proxy settings to the ``TelegramClient`` constructor: .. code:: python >>> from telethon import TelegramClient >>> import socks >>> client = TelegramClient('session_id', ... api_id=12345, api_hash='0123456789abcdef0123456789abcdef', ... proxy=(socks.SOCKS5, 'localhost', 4444)) The ``proxy=`` argument should be a tuple, a list or a dict, consisting of parameters described `here `_. API status ---------- In an attempt to help everyone who works with the Telegram API, Telethon will by default report all Remote Procedure Call errors to `PWRTelegram `_, a public database anyone can query, made by `Daniil `_. All the information sent is a ``GET`` request with the error code, error message and method used. If you still would like to opt out, simply set ``client.session.report_errors = False`` to disable this feature. However Daniil would really thank you if you helped him (and everyone) by keeping it on!