# Python Trio Library

Trio is a modern library for asynchronous concurrency in Python. It is designed to be easier to use and harder to make mistakes with than `asyncio`, focusing on "structured concurrency".

## Installation

```bash
pip install trio
```

## Basic Usage

Trio uses `async`/`await` syntax but requires a `trio.run()` entry point.

```python
import trio

async def main():
    print("Hello")
    await trio.sleep(1)
    print("World")

trio.run(main)
```

## Nurseries (Structured Concurrency)

In Trio, you spawn tasks inside a "nursery". The nursery block doesn't exit until all tasks inside it have completed.

```python
import trio

async def child1():
    print("Child 1 started")
    await trio.sleep(1)
    print("Child 1 finished")

async def child2():
    print("Child 2 started")
    await trio.sleep(0.5)
    print("Child 2 finished")

async def main():
    async with trio.open_nursery() as nursery:
        nursery.start_soon(child1)
        nursery.start_soon(child2)
    print("All children finished")

trio.run(main)
```

## Timeouts

Trio makes timeouts easy and safe with context managers.

```python
import trio

async def main():
    with trio.move_on_after(2):
        await trio.sleep(5)
        print("This won't print")
    print("Timeout expired, continuing...")

trio.run(main)
```

## Cancellation

Cancellation is handled via "cancel scopes".

```python
import trio

async def main():
    with trio.CancelScope() as scope:
        scope.cancel()
        await trio.sleep(1)
        print("This won't print")

trio.run(main)
```

[[programming/python/python]]