Pyeventbus: a publish/subscribe event bus

Last update: Apr 21, 2022

Overview

pyeventbus

pyeventbus is a publish/subscribe event bus for Python 2.7.

simplifies the communication between python classes
decouples event senders and receivers
performs well threads, greenlets, queues and concurrent processes
avoids complex and error-prone dependencies and life cycle issues
makes code simpler
has advanced features like delivery threads, workers and spawning different processes, etc.
is tiny (3KB archive)

pyeventbus in 3 steps:

Define events:

class MessageEvent:
    # Additional fields and methods if needed
    def __init__(self):
        pass

Prepare subscribers: Declare and annotate your subscribing method, optionally specify a thread mode:

from pyeventbus import *

@subscribe(onEvent=MessageEvent)
def func(self, event):
    # Do something
    pass

from pyeventbus import *

class MyClass:
    def __init__(self):
        pass

    def register(self, myclass):
        PyBus.Instance().register(myclass, self.__class__.__name__)

# then during initilization

myclass = MyClass()
myclass.register(myclass)

Post events:

from pyeventbus import *

class MyClass:
    def __init__(self):
        pass

    def register(self, myclass):
        PyBus.Instance().register(myclass, self.__class__.__name__)

    def postingAnEvent(self):
        PyBus.Instance().post(MessageEvent())

 myclass = MyClass()
 myclass.register(myclass)
 myclass.postingAnEvent()

Modes: pyeventbus can run the subscribing methods in 5 different modes

POSTING:

Runs the method in the same thread as posted. For example, if an event is posted from main thread, the subscribing method also runs in the main thread. If an event is posted in a seperate thread, the subscribing method runs in the same seperate method

This is the default mode, if no mode has been provided::

@subscribe(threadMode = Mode.POSTING, onEvent=MessageEvent)
def func(self, event):
    # Do something
    pass

PARALLEL:

Runs the method in a seperate python thread::

@subscribe(threadMode = Mode.PARALLEL, onEvent=MessageEvent)
def func(self, event):
    # Do something
    pass

GREENLET:

Runs the method in a greenlet using gevent library::

@subscribe(threadMode = Mode.GREENLET, onEvent=MessageEvent)
def func(self, event):
    # Do something
    pass

BACKGROUND:

Adds the subscribing methods to a queue which is executed by workers::

@subscribe(threadMode = Mode.BACKGROUND, onEvent=MessageEvent)
def func(self, event):
    # Do something
    pass

CONCURRENT:

Runs the method in a seperate python process::

@subscribe(threadMode = Mode.CONCURRENT, onEvent=MessageEvent)
def func(self, event):
    # Do something
    pass

Adding pyeventbus to your project:

pip install pyeventbus

Example:

git clone https://github.com/n89nanda/pyeventbus.git

cd pyeventbus

virtualenv venv

source venv/bin/activate

pip install pyeventbus

python example.py

Benchmarks and Performance:

Refer /pyeventbus/tests/benchmarks.txt for performance benchmarks on CPU, I/O and networks heavy tasks.

Run /pyeventbus/tests/test.sh to generate the same benchmarks.

Performance comparison between all the modes with Python and Cython

Inspiration

Inspired by Eventbus from greenrobot: https://github.com/greenrobot/EventBus

You might also like...

Code for the paper "Unsupervised Contrastive Learning of Sound Event Representations", ICASSP 2021.

Unsupervised Contrastive Learning of Sound Event Representations This repository contains the code for the following paper. If you use this code or pa

81 Dec 22, 2022

Repo for "Event-Stream Representation for Human Gaits Identification Using Deep Neural Networks"

Summary This is the code for the paper Event-Stream Representation for Human Gaits Identification Using Deep Neural Networks by Yanxiang Wang, Xian Zh

54 Jan 3, 2023

Cross-media Structured Common Space for Multimedia Event Extraction (ACL2020)

Cross-media Structured Common Space for Multimedia Event Extraction Table of Contents Overview Requirements Data Quickstart Citation Overview The code

49 Nov 21, 2022

CVPRW 2021: How to calibrate your event camera

E2Calib: How to Calibrate Your Event Camera This repository contains code that implements video reconstruction from event data for calibration as desc

104 Nov 16, 2022

Repository relating to the CVPR21 paper TimeLens: Event-based Video Frame Interpolation

TimeLens: Event-based Video Frame Interpolation This repository is about the High Speed Event and RGB (HS-ERGB) dataset, used in the 2021 CVPR paper T

544 Dec 19, 2022

An implementation for `Text2Event: Controllable Sequence-to-Structure Generation for End-to-end Event Extraction`

Text2Event An implementation for Text2Event: Controllable Sequence-to-Structure Generation for End-to-end Event Extraction Please contact Yaojie Lu (@

153 Jan 7, 2023

Official PyTorch implementation of N-ImageNet: Towards Robust, Fine-Grained Object Recognition with Event Cameras (ICCV 2021)

N-ImageNet: Towards Robust, Fine-Grained Object Recognition with Event Cameras Official PyTorch implementation of N-ImageNet: Towards Robust, Fine-Gra

32 Dec 26, 2022

SurvITE: Learning Heterogeneous Treatment Effects from Time-to-Event Data

SurvITE: Learning Heterogeneous Treatment Effects from Time-to-Event Data SurvITE: Learning Heterogeneous Treatment Effects from Time-to-Event Data Au

14 Nov 28, 2022

Weakly Supervised Dense Event Captioning in Videos, i.e. generating multiple sentence descriptions for a video in a weakly-supervised manner.

WSDEC This is the official repo for our NeurIPS paper Weakly Supervised Dense Event Captioning in Videos. Description Repo directories ./: global conf

96 Nov 1, 2022

Comments

Same method name for multiple subscribers bug

Please see the code below. To summarize:

Define one event
Define two subscriber listening for the event above. Each subscriber has a listener method with the name on_event
Each of the subscriber classes above defines an instance field, but with unique name (self.something in the first class, self.something2 in the second class)
Define another class that posts an event

Run this scenario and get the error below:

Exception in thread thread-on_event:
Traceback (most recent call last):
  File "C:\Anaconda2\envs\python\lib\threading.py", line 801, in __bootstrap_inner
    self.run()
  File "C:\Anaconda2\envs\python\lib\site-packages\pyeventbus\pyeventbus.py", line 112, in run
    self.method(self.subscriber, self.event)
  File "C:/FractureID/projects/python/ui/spectraqc/PyEventBusBug.py", line 16, in on_event
    print (self.something)
AttributeError: Subscriber2 instance has no attribute 'something'

Exception in thread thread-on_event:
Traceback (most recent call last):
  File "C:\Anaconda2\envs\python\lib\threading.py", line 801, in __bootstrap_inner
    self.run()
  File "C:\Anaconda2\envs\python\lib\site-packages\pyeventbus\pyeventbus.py", line 112, in run
    self.method(self.subscriber, self.event)
  File "C:/FractureID/projects/python/ui/spectraqc/PyEventBusBug.py", line 26, in on_event
    print (self.something_else)
AttributeError: Subscriber1 instance has no attribute 'something_else'

It complains about the variable in class two not having the attribute in the first class and the other way around.

If I change on of the on_event to something else like on_event2 then the issue is gone.

from pyeventbus import *


class SomeEvent:
    def __init__(self):
        pass


class Subscriber1:
    def __init__(self):
        self.something = 'First subscriber'
        PyBus.Instance().register(self, self.__class__.__name__)

    @subscribe(threadMode=Mode.PARALLEL, onEvent=SomeEvent)
    def on_event(self, event):
        print (self.something)


class Subscriber2:
    def __init__(self):
        self.something_else = 'Second subscriber'
        PyBus.Instance().register(self, self.__class__.__name__)

    @subscribe(threadMode=Mode.PARALLEL, onEvent=SomeEvent)
    def on_event(self, event):
        print (self.something_else)


class PyEventBusBug:

    def __init__(self):
        Subscriber1()
        Subscriber2()
        PyBus.Instance().post(SomeEvent())


if __name__ == "__main__":
    PyEventBusBug()

bug

opened by ddanny 0

Doesn't even start on Windows because 2000 threads is apparently too much

  File "C:\Python27\lib\site-packages\pyeventbus\pyeventbus.py", line 116, in subscribe
    bus = PyBus.Instance()
  File "C:\Python27\lib\site-packages\pyeventbus\Singleton.py", line 30, in Instance
    self._instance = self._decorated()
  File "C:\Python27\lib\site-packages\pyeventbus\pyeventbus.py", line 24, in __init__
    for worker in [lambda: self.startWorkers() for i in range(self.num_threads)]: worker()
  File "C:\Python27\lib\site-packages\pyeventbus\pyeventbus.py", line 24, in <lambda>
    for worker in [lambda: self.startWorkers() for i in range(self.num_threads)]: worker()
  File "C:\Python27\lib\site-packages\pyeventbus\pyeventbus.py", line 30, in startWorkers
    worker.start()
  File "C:\Python27\lib\threading.py", line 736, in start
    _start_new_thread(self.__bootstrap, ())
thread.error: can't start new thread

See also: https://stackoverflow.com/a/1835043/2583080

bug

opened by PawelTroka 4

Releases(0.2)

0.2(Feb 2, 2018)

added performance benchmarks and tests
Source code(tar.gz)
Source code(zip)
0.1(Feb 2, 2018)

first stable release
Source code(tar.gz)
Source code(zip)

Owner

GitHub Repository

Shitty gaze mouse controller

demo.mp4 shitty_gaze_mouse_cotroller install tensofflow, cv2 run the main.py and as it starts it will collect data so first raise your left eyebrow(bo

16 Aug 30, 2022

GEP (GDB Enhanced Prompt) - a GDB plug-in for GDB command prompt with fzf history search, fish-like autosuggestions, auto-completion with floating window, partial string matching in history, and more!

GEP (GDB Enhanced Prompt) GEP (GDB Enhanced Prompt) is a GDB plug-in which make your GDB command prompt more convenient and flexibility. Why I need th

23 Dec 21, 2022

Implementation for our ICCV2021 paper: Internal Video Inpainting by Implicit Long-range Propagation

Implicit Internal Video Inpainting Implementation for our ICCV2021 paper: Internal Video Inpainting by Implicit Long-range Propagation paper | project

202 Dec 30, 2022

Benchmark datasets, data loaders, and evaluators for graph machine learning

Overview The Open Graph Benchmark (OGB) is a collection of benchmark datasets, data loaders, and evaluators for graph machine learning. Datasets cover

1.5k Jan 05, 2023

NeoDTI: Neural integration of neighbor information from a heterogeneous network for discovering new drug-target interactions

NeoDTI NeoDTI: Neural integration of neighbor information from a heterogeneous network for discovering new drug-target interactions (Bioinformatics).

62 Nov 26, 2022

Robust Video Matting in PyTorch, TensorFlow, TensorFlow.js, ONNX, CoreML!

6.5k Jan 04, 2023

Source code for our CVPR 2019 paper - PPGNet: Learning Point-Pair Graph for Line Segment Detection

PPGNet: Learning Point-Pair Graph for Line Segment Detection PyTorch implementation of our CVPR 2019 paper: PPGNet: Learning Point-Pair Graph for Line

170 Oct 25, 2022

Cross View SLAM

Cross View SLAM This is the associated code and dataset repository for our paper I. D. Miller et al., "Any Way You Look at It: Semantic Crossview Loca

99 Dec 09, 2022

Code for "Unsupervised State Representation Learning in Atari"

Unsupervised State Representation Learning in Atari Ankesh Anand*, Evan Racah*, Sherjil Ozair*, Yoshua Bengio, Marc-Alexandre Côté, R Devon Hjelm This

217 Jan 03, 2023

TensorFlow Tutorial and Examples for Beginners (support TF v1 & v2)

TensorFlow Examples This tutorial was designed for easily diving into TensorFlow, through examples. For readability, it includes both notebooks and so

42.5k Jan 08, 2023

Membership Inference Attack against Graph Neural Networks

MIA GNN Project Starter If you meet the version mismatch error for Lasagne library, please use following command to upgrade Lasagne library. pip insta

6 Nov 09, 2022

This repository contains the code to replicate the analysis from the paper "Moving On - Investigating Inventors' Ethnic Origins Using Supervised Learning"

Replication Code for 'Moving On' - Investigating Inventors' Ethnic Origins Using Supervised Learning This repository contains the code to replicate th

0 Jan 04, 2022