Async Iterator¶

Some API functions return an « async iterator ». An async iterator is something that is capable of being used in an async for statement.

These async iterators can be used as follows:

async for elem in channel.history():
    # do stuff with elem here

Certain utilities make working with async iterators easier, detailed below.

class discord.AsyncIterator¶

Represents the « AsyncIterator » concept. Note that no such class exists, it is purely abstract.

async for x in y: Iterates over the contents of the async iterator.

await next()¶

This function is a coroutine.

Advances the iterator by one, if possible. If no more items are found then this raises NoMoreItems.

await get(**attrs)¶

This function is a coroutine.

Similar to utils.get() except run over the async iterator.

Getting the last message by a user named “Dave” or None:

msg = await channel.history().get(author__name='Dave')

await find(predicate)¶

This function is a coroutine.

Similar to utils.find() except run over the async iterator.

Unlike utils.find(), the predicate provided can be a coroutine.

Getting the last audit log with a reason or None:

def predicate(event):
    return event.reason is not None

event = await guild.audit_logs().find(predicate)

Paramètres:: predicate – The predicate to use. Could be a coroutine.
Renvoie:: The first element that returns True for the predicate or None.

await flatten()¶

This function is a coroutine.

Flattens the async iterator into a list with all the elements.

Renvoie:: A list of every element in the async iterator.
Type renvoyé:: list

chunk(max_size)¶

Collects items into chunks of up to a given maximum size. Another AsyncIterator is returned which collects items into lists of a given size. The maximum chunk size must be a positive integer.

Ajouté dans la version 1.6.

Collecting groups of users:

async for leader, *users in reaction.users().chunk(3):
    ...

Avertissement

The last chunk collected may not be as large as max_size.

Paramètres:: max_size – The size of individual chunks.
Type renvoyé:: AsyncIterator

map(func)¶

This is similar to the built-in map function. Another AsyncIterator is returned that executes the function on every element it is iterating over. This function can either be a regular function or a coroutine.

Creating a content iterator:

def transform(message):
    return message.content

async for content in channel.history().map(transform):
    message_length = len(content)

Paramètres:: func – The function to call on every element. Could be a coroutine.
Type renvoyé:: AsyncIterator

filter(predicate)¶

This is similar to the built-in filter function. Another AsyncIterator is returned that filters over the original async iterator. This predicate can be a regular function or a coroutine.

Getting messages by non-bot accounts:

def predicate(message):
    return not message.author.bot

async for elem in channel.history().filter(predicate):
    ...

Paramètres:: predicate – The predicate to call on every element. Could be a coroutine.
Type renvoyé:: AsyncIterator