Event-Driven asyncio: A Case Study of Trio's API(PyCon US 2024)

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Event-Driven asyncio: A Case Study of Trio's API Junya Fukuda PyCon US 2024

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Who am I? 👤 •Junya Fukudaʢ@JunyaFffʣcalled “Jun” not “Junior” •Photos 📷 SNS post 👍 •Software Engineer at Groove X, inc. Here is today's code

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Who am I? 👤 •book •Python Practical Recipes Here is today's code •Junya Fukudaʢ@JunyaFffʣcalled “Jun” not “Junior” •Photos 📷 SNS post 👍 •Software Engineer at Groove X, inc.

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Who am I? 👤 •Expert Python Programming - Fourth Edition •Written by Tarek Ziadé, Michał Jaworski Here is today's code •Junya Fukudaʢ@JunyaFffʣcalled “Jun” not “Junior” •Photos 📷 SNS post 👍 •Software Engineer at Groove X, inc. •book •Python Practical Recipes

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Who am I? 👤 •Expert Python Programming - Fourth Edition •Written by Tarek Ziadé, Michał Jaworski •Junya Fukudaʢ@JunyaFffʣcalled “Jun” not “Junior” •Photos 📷 SNS post 👍 •Software Engineer at Groove X, inc. •book •Python Practical Recipes Here is today's code

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Thank you 🙏 I love Python async 🌷

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Event-Driven async A Case Study of Trio's API

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Python async, are you using it? ✋

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Python async, are you using it? ✋ Thank You!

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Python async, are you using it? ✋ Web? ✋

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Python async, are you using it? ✋ Web? ✋ Database? ✋

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Python async, are you using it? ✋ Web? ✋ Database? ✋ API calls? ✋

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Python async, are you using it? ✋ Web? ✋ Database? ✋ API calls? ✋ Tasks? ✋

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Trio? ✋ ✋ ✋

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🤝🤝🤝🤝🤝

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We use it in robotics.

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Event-Driven async A Case Study of Trio's API

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Event-Driven async A Case Study of Trio's API in production

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Event-Driven async A Case Study of Trio's API in production

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Today's Goal •Python async and robot use case

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Today's Goal •Python async and robot use case •Event-Driven Example in Robot Development - Handling Multiple Inputs

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Today's Goal •Python async and robot use case •Event-Driven Example in Robot Development - Handling Multiple Inputs •About Trio and Trio-util, asyncio

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Today's Goal •Python async and robot use case •Event-Driven Example in Robot Development - Handling Multiple Inputs •About Trio and Trio-util, asyncio AsyncValue class

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Today's Goal •Python async and robot use case •Event-Driven Example in Robot Development - Handling Multiple Inputs •About Trio and Trio-util, asyncio AsyncValue class •Handling Many Inputs in Async Apps - AsyncValue

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Today's Agenda •Python async and robot use case •Event-Driven Example in Robot Development - Handling Multiple Inputs

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Today's Agenda •Python async and robot use case •Event-Driven Example in Robot Development - Handling Multiple Inputs •Why Python Async •Why Trio

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Today's Agenda •Python async and robot use case •Event-Driven Example in Robot Development - Handling Multiple Inputs •Why Python Async •Why Trio

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•Python async and robot use case

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Why we chose Python Async for the robot decision-making engine

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Why Python Async

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Why Python Async •Their name is LOVOT

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Why Python Async •Their name is LOVOTʢ "LOVE" ❤ and "ROBOT 🤖"ʣ

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Why Python Async •Their name is LOVOT •Over 10,000 sold in Japan

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Why Python Async •Their name is LOVOT •Over 10,000 sold in Japan •Equipped with many sensors

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Why Python Async •൴Β͸֎ͷ৘ใΛͨ͘͞Μಘ͍ͯΔ

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Why Python Async •൴Β͸֎ͷ৘ใΛͨ͘͞Μಘ͍ͯΔ &RVJQQFEXJUIPWFS$16DPSFT PWFS.$6T BOEPWFSTFOTPST

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Why Python Async •Their name is LOVOT •Over 10,000 sold in Japan •Equipped with many sensors •Decision-Making and Environment

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Why Python Async •Running many microservices

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Why Python Async •Hardware-level information and cloud integration •Running many microservices

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Why Python Async •Hardware-level information and cloud integration •Running many microservices •Limited HW resources

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Why Python Async •Equipped with many sensors - many I/O •Limited HW resources

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Why Python Async •Equipped with many sensors - many I/O •Limited HW resources

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Why Python Async •Equipped with many sensors - many I/O •Limited HW resources • Python Async is perfect

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Why Trio instead of asyncio?

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Why Trio? •Structured Concurrency

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Why Trio? •Robust cancellation •Structured Concurrency

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Why Trio? •Robust cancellation •Structured Concurrency •User-friendly API

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Why Trio? •Robust cancellation •Structured Concurrency •User-friendly API •However, this decision was made in the summer of 2017

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Why Trio? •Robust cancellation •Structured Concurrency •User-friendly API No high-level APIs yet 😢 •However, this decision was made in the summer of 2017

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Why do we need a user-friendly APIʁ 🤔

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Why Trio? Python Engineers

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Why Trio? Python Engineers

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Why Trio? Python Engineers

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Why Trio? Python Engineers Animators

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Why Trio? Python Engineers Animators

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Why Trio? Python Engineers Animators Kawaii Behavior

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Why Trio? •Why do we need a user-friendly APIʁ •Animators also needed to write code.

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Why Trio? •Why do we need a user-friendly APIʁ •Animators also needed to write code. 8F DIPTF 5SJP

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•Event-Driven Example in Robot Development - Handling Multiple Inputs

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•Event-Driven Example in Robot Development - Handling Multiple Inputs

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Handling Multiple Inputs •Continuously watch for value changes

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Handling Multiple Inputs •Continuously watch for value changes 👀

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async def main(): async with trio.open_nursery() as nursery: event1 = AsyncValue("idel 🤖😢") event2 = AsyncValue("idel 🤖😆") nursery.start_soon(fetch, event1, event2) with compose_values(event1=event1, event2=event2) as comp_event: async for v in comp_event.eventual_values(): print(f"doing something cute 🤖 {v=}“) •Continuously watch for value changes 👀

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•Continuously watch for value changes 👀 async def main(): async with trio.open_nursery() as nursery: event1 = AsyncValue("idel 🤖😢") event2 = AsyncValue("idel 🤖😆") nursery.start_soon(fetch, event1, event2) with compose_values(event1=event1, event2=event2) as comp_event: async for v in comp_event.eventual_values(): print(f"doing something cute 🤖 {v=}“)

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•Continuously watch for value changes 👀

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Handling Multiple Inputs •AsyncValue Class 👀

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Handling Multiple Inputs •AsyncValue Class 👀 •from trio-util

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Handling Multiple Inputs •AsyncValue Class 👀 •from trio-util •wraps any value or awaitable

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Handling Multiple Inputs •Inside AsyncValue •_async_value.py •class _ValueWrapper: •class _WaitQueue: •class _Result: •class _RefCountedDefaultDict

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class _ValueWrapper: … def __hash__(self): try: return hash(self.value) except TypeError: return super().__hash__() def __eq__(self, other): return self.value.__eq__(other.value) def __call__(self, x, *args): return x == self.value •class _ValueWrapper:

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class _RefCountedDefaultDict(defaultdict): """defaultdict offering deterministic collection of unreferenced keys""" … @contextmanager def open_ref(self, key): try: yield self[key] finally: self.refs_by_key[key] -= 1 if self.refs_by_key[key] == 0: del self[key] del self.refs_by_key[key] •class _RefCountedDefaultDict

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Handling Multiple Inputs •Inside AsyncValue •Value Storage and Setting •Waiting for Value Changes: •Waiting for Transitions •Iterating Over Transitions •Waiting for Value Changes:

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Handling Multiple Inputs •Event-Driven API Approach •Trio-util IUUQTHJUIVCDPN HSPPWFYUSJPVUJM

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Handling Multiple Inputs •In the case of asyncio: •There is no API that performs the same function. •Synchronization Primitives •asyncio.Event, asyncio.Condition

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Handling Multiple Inputs •Trio-util does not support anyio yet •There is no API that performs the same function. •asyncio-util IUUQTHJUIVCDPNKSGLBTZODJPVUJM Here is today's code

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reference •Simplifying Python's Async with Trio •https://talkpython.fm/episodes/show/167/simplifying-pythons-async-with-trio •Higher level Python asyncio with AnyIO •https://talkpython.fm/episodes/show/385/higher-level-python-asyncio-with-anyio •groove-x / trio-util •https://github.com/groove-x/trio-util •Structured Concurrency - Martin Sústrik •https://250bpm.com/blog:71/

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Would you like to see them?

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Groove X will be a sponsor of PyCon JP 2024. See you in Tokyo. Sep27-28 2024

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Groove X will be a sponsor of PyCon JP 2024. See you in Tokyo. Sep27-28 2024

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Thank you for your attention 👋

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Do you have a any Question? Feel free to ask questions on Twitter. (@junya ff f)