Paginator for discord.py

paginator.py

import collections.abc
import typing
import itertools
import asyncio

import discord
from discord.ext import commands


class Paginator:

    def __init__(self, ctx: commands.Context, entries: list,
                 information: typing.Optional[collections.abc.Iterable] = None,
                 formatter: typing.Callable = None,
                 max_per_page: int = 5, reaction_timeout: float = 40.0):
        self.index = 0
        self.limit = max_per_page
        self.timeout = reaction_timeout
        self.pages = self.paginate(entries)
        self.count = len(self.pages)
        self.formatter = formatter if formatter is not None else self.format

        self.title, self.description = information if information else ('Please specify a title.',
                                                                        'Please specify a description.')
        self.channel: discord.TextChannel = ctx.channel
        self.bot: commands.Bot = ctx.bot

        self.message: discord.Message = None

        self.reactions = {
            '⏮': self.front,
            '⬅': self.previous,
            '➡': self.next,
            '⏭': self.end
        }

    def format(self, elements: collections.abc.Iterable):
        return "\n".join((element for element in elements if element is not None))

    def paginate(self, iterable: collections.abc.Iterable):
        args = [iter(iterable)] * self.limit
        return tuple(itertools.zip_longest(*args))

    async def start(self):
        await self.turn()

        def check(reaction: discord.Reaction, user):
            return str(reaction.emoji) in self.reactions and not user.bot

        while True:
            try:
                reaction, user = await self.bot.wait_for('reaction_add', check=check, timeout=self.timeout)
                await self.reactions[str(reaction.emoji)]()
                await self.message.remove_reaction(str(reaction.emoji), user)

            except asyncio.TimeoutError:
                await self.message.clear_reactions()

                break

    async def turn(self):
        content = self.pages[self.index]
        formatted = self.formatter(content)

        if not isinstance(formatted, discord.Embed):
            embed = discord.Embed(title=self.title, description=self.description)
            embed.add_field(name=f'Page {self.index + 1} of {self.count}', value=formatted)
        else:
            embed = formatted

        if self.message is not None:
            await self.message.clear_reactions()
            await self.message.edit(embed=embed)
        else:
            self.message = await self.channel.send(embed=embed)

        if self.index > 0:
            await self.message.add_reaction('⏮')
            await self.message.add_reaction('⬅')

        if self.index < self.count - 1:
            await self.message.add_reaction('➡')

        if self.index <= self.count - 2:
            await self.message.add_reaction('⏭')

    async def next(self):
        self.index += 1
        await self.turn()

    async def previous(self):
        self.index -= 1
        await self.turn()

    async def front(self):
        self.index = 0
        await self.turn()

    async def end(self):
        self.index = self.count - 1
        await self.turn()