Hi. Two issues:

• You are using a boolean value where an integer is required. archived_only is boolean but the method works with integer folder ids.
• This method is not that trivial to deal with. Telegram works with an optional folder id. If you don't pass it you'll get all dialogs, if you pass 0 you get the non-archived dialogs, if you pass 1 you get the archived dialogs. With your solution we are missing one case.

I believe the whole method needs a rewrite to allow an easier implementation and usage, in order to allow every possible case. Maybe pinned dialogs should also be fetched using a separate convenience method?

You're correct about those issues, I used archived_only as a boolean since it's a subclass of int and to pass None to it directly to fetch all dialogs (which is dirty), but that doesn't seem suitable for folder_id anymore, plus it would fail with GetPinnedDialogs since folder_id isn't optional there. My apologises for not testing all the possible scenarios.

I also looked a bit into GetPinnedDialogs, GetDialogs and GetPeerDialogs (new get_dialog method maybe), having separate methods for them should be better. Maybe move the common dialog parsing code into a function outside the class and separate the methods in their classes respectively rather making a new file to avoid boilerplate?

Also, currently GetDialogs has a limit of only retrieving 100 dialogs the most, perhaps we could call iter_dialogs inside get_dialogs to make better use of the limit argument and rename pinned_only to exclude_pinned to match the raw method more?