async — Expert Playground

Declares an asynchronous coroutine function or context manager

Python Playground

import asyncio
import inspect
import dis

async def example():
    await asyncio.sleep(0)
    return 42

# Coroutine object
coro = example()
print(f"Type: {type(coro)}")
print(f"Is coroutine: {inspect.iscoroutine(coro)}")
print(f"State: {inspect.getcoroutinestate(coro)}")

# Must close or run it
coro.close()

# Bytecode
print(f"\nBytecode:")
dis.dis(example)

# async def compiles similarly to regular def
# but the code object has CO_COROUTINE flag
print(f"\nFlags: {example.__code__.co_flags}")
print(f"Is coroutine func: {inspect.iscoroutinefunction(example)}")

Output

Click "Run" to execute your code

async def sets the CO_COROUTINE flag on the code object. The bytecode uses GET_AWAITABLE and SEND to implement await. Coroutine objects track their state (created, running, suspended, closed).

Challenge

Try modifying the code above to explore different behaviors. Can you extend the example to handle a new use case?

View all Expert examples for async