promisio

JavaScript-style async programming for Python.

Examples

Create a promise-based async function using the promisify decorator. It works on both sync and async functions!

from promisio import promisify

@promisify
async def f():
    await asyncio.sleep(1)
    return 42

@promisify
def g(x):
    return x * 2

async def main():
    print(await f())  # prints 42
    print(await g(42))  # prints 84

    promise = f()  # runs function in the background without waiting
    # ... do other stuff here in parallel with f running
    await promise  # finally wait for f to complete

The return value of the decorated function is a JavaScript-style promise object that can be awaited. The then(), catch() and finally_() methods to chain promises work as in JavaScript. The Promise.all(), Promise.all_settled(), Promise.any(), Promise.race(), Promise.resolve() and Promise.reject() are also available. Promises in this package are extended to also support cancellation via the cancel() and cancelled() methods.

Resources

• Documentation
• PyPI
• Change Log