PyEventEngine 0.4.6

Python Basic EventEngine

PyEventEngine

High-performance, topic-driven event engine for Python with a Cython-accelerated core and a native Python fallback.

• Fast publish/subscribe event routing by topic (exact + generic wildcard/pattern matching)
• Clean, typed API with drop-in fallback when C extensions are unavailable
• Built-in timers, handler stats (EventHookEx), and convenient formatting helpers

Installation

pip install PyEventEngine

Or install from source:

pip install git+https://github.com/BolunHan/PyEventEngine.git

Quick Start

import time

from event_engine import EventEngine, Topic, EventHook

# Create and start the engine
engine = EventEngine(capacity=8192)
engine.start()

# Register a handler for an exact topic
exact = Topic('Demo.Hello')

def hello_handler(name: str, topic=None):
    print(f"Hello {name} from {topic.value if topic else 'N/A'}")

engine.register_handler(exact, hello_handler)

# Publish a message
engine.put(exact, 'World')

# Clean up
time.sleep(0.1)
engine.stop()
engine.clear()

Generic topics (wildcards/patterns)

import time
from event_engine import Topic, EventEngine

engine = EventEngine()
pattern = Topic('Demo.{what}')

calls = []


def f(what: str, topic=None):
    calls.append((what, topic.value))


engine.register_handler(pattern, f)

engine.start()
engine.put(Topic('Demo.Test'), 'a test sub-topic')
engine.put(Topic('Demo.Live'), 'a live sub-topic')
time.sleep(0.1)  # allow some time for processing
engine.stop()

print(calls)  # [('a test sub-topic', 'Demo.Test'), ('a live sub-topic', 'Demo.Live')]

Timers (EventEngineEx)

from event_engine import EventEngine, EventEngineBase, EventEngine as EventEngineEx, Topic

engine = EventEngineEx(capacity=4096)
engine.start()

# Create a 1-second timer topic and subscribe
timer_topic = engine.get_timer(1.0)
engine.register_handler(timer_topic, lambda **kw: print('tick', kw))

# ... run a little while
import time; time.sleep(3)
engine.stop(); engine.clear()

Logging

By default, the package uses a colored logger under event_engine.base. To integrate with your application's logging, call set_logger once after import. It will propagate to submodules.

import logging
from event_engine import set_logger

logger = logging.getLogger('MyApp')
logger.setLevel(logging.INFO)
set_logger(logger)

Fallback behavior

On import, the package tries to use the Cython implementation (event_engine.capi). If that fails (e.g., no compiler available), it automatically falls back to the native Python implementation (event_engine.native). You can check the active backend via:

from event_engine import USING_FALLBACK
print('Using native fallback?' , USING_FALLBACK)

Development

• Run unit tests and demos under demo/
• Native performance test: python demo/native_performance_test.py
• CAPI performance test (requires compiled extensions): python demo/capi_performance_test.py

Documentation

Full documentation is available at: https://bolunhan.github.io/PyEventEngine/ (auto-generated from main branch)

To build documentation locally, see docs/BUILD.md.

---

See demo/ for more examples: matching, timers, performance. Issues and PRs welcome!