tools.py

from dbmodels import Usernames


def get_uid(update):                                                                       # this makes your life easier
    return update.effective_message.from_user.id


def get_cid(update):                                                                       # this makes your life easier
    return update.effective_message.chat.id


def store_name(update):                                                        # this function is here only for /tacotop

    username = Usernames.select().where(Usernames.uid == get_uid(update))
    if username.exists():
        return username.get().name

    user = update.effective_message.from_user
    if user.username is None:
        first_name = user.first_name
        last_name = user.last_name
        if last_name is None:
            name = first_name
        else:
            name = first_name + ' ' + last_name
    else:
        name = '@' + user.username

    Usernames.create(uid=get_uid(update),
                     name=name)
    return name


def resolve_name(uid):                                                               # returns username if present in DB
    user = Usernames.select().where(Usernames.uid == uid)
    if user.exists():
        return user.get().name
    else:
        return uid