We have constants in different locations, e.g.

• telegram.constants
• class attributes of telegram.ParseMode
• class attributes of telegram.Dice

That should be unified, i.e.:

• Gather all constants in telegram.constants (I guess a regex-search for SCREAMING_SNAIL_CASE should do the trick …)
• Repace the class attributes by links to the constant from telegram.constant, (e.g. ParseMode.HTML = constants.PARSE_MODE_HTML)
• Add additional links, where suitable (e.g. Message.MAX_LENGTH = constants.MAX_MESSAGE_LENGTH)

Moreover, in light of the recent TG update, we should add

• constants for user ID 777000 and 1087968824, which act as senders for forwarded channel posts and messages from anonymous admins (see here)
• Add properties is_anonymous_admin and is_service_chat (or similar namings) to User and Chat that compare the user/chat_id to the IDs menotioned above

Edit: there should be notes on the constants, if they are not documented. And going through the docs to see if there are constants not covered already probably won't hurt …