pykka

library4.4.2pypypi✓ verified 88d ago

Pykka is a Python implementation of the actor model, providing concurrency primitives for building distributed and concurrent systems. Version 4.4.2 runs on Python >=3.10. New releases are sporadic.

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pip install pykka

github ↗package ↗homepage ↗docs ↗

INSTALL

IMPORT

SIG · PYKKA

pykka

workflowpythonv4.4.2

Install

1.6s avg

Import

61ms

Disk

16MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v4.4.2 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.95 runs

installs and imports cleanly · install 0.0s · import 0.062s · 18MB

glibc

py 3.10–3.95 runs

installs and imports cleanly · install 1.6s · import 0.060s · 18MB

16MB installed

● package 16MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

Actor

✓ from pykka import Actor

Standard import

ThreadingActor

✓ from pykka import ThreadingActor

Preferred for I/O-bound tasks

ActorRef

✓ from pykka import ActorRef

Reference to an actor instance

ActorRegistry

✓ from pykka import ActorRegistry

Global registry of actors

getattr

✓ from pykka import getattr

✗ from pykka.actor import getattr

getattr moved to top-level since v3

Define an actor class, start it, send a message, and stop.

import pykka class Greeter(pykka.ThreadingActor): def __init__(self, greeting='Hi'): super().__init__() self.greeting = greeting def on_receive(self, message): return f'{self.greeting}, {message}' actor = Greeter.start(greeting='Hello').proxy() print(actor.on_receive('World').get()) # Hello, World actor.stop()

Debug

Known issues

gotchaActors are not threadsafe; avoid sharing mutable state between actors. Use message passing only.

fix

Design actors as isolated units communicating via messages (dicts or immutable objects).

affects: all

gotchaUnlike the standard library, Pykka actors must be stopped explicitly to release resources. ActorRegistry will not clean them up automatically.

fix

Call actor.stop() or use a context manager: with Greeter.start() as actor: ...

affects: >=3.0

breakingIn Pykka 4.x, on_receive must return a value or raise an exception; previously None was allowed and would cause hangs.

fix

Ensure on_receive always returns a value (or call actor.stop() explicitly without a return).

affects: 4.0 - 4.4

gotchaProxy() and get() are blocking. Using them inside an actor's on_receive can cause deadlocks.

fix

Use future.get() only outside actors, or use call() with a callback instead.

affects: all

Errors

Common errors & fixes

ModuleNotFoundError: No module named 'pykka'

Pykka not installed or wrong Python environment.

fix

Install with 'pip install pykka' and verify Python version >=3.10.

AttributeError: 'MyActor' object has no attribute 'start'

Attempting to call start() on an instance instead of the class.

fix

Use MyActor.start() (class method) not my_actor.start().

TimeoutError: Actor call timed out after ... seconds

Actor's on_receive never returned a value (or deadlocked).

fix

Ensure every on_receive returns a result. If no result, call actor.stop() and return a default.

Upgrade

Version history

4.4.2latest on PyPI · released Mar 14, 2026

Audit

Dependencies

No dependency data recorded yet.

Agent activity

40 hits · last 30 days

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Anthropic

OpenAI (training)

Resources

githubhttps://github.com/jodal/pykka ↗

packagehttps://pypi.org/project/pykka/ ↗

homepagehttps://pykka.org ↗

docshttps://pykka.readthedocs.io/ ↗