Asynchronous programming is not multithreading or multiprocessing. Instead, it is concurrent programming where we can run a potentially long-running task and allow our program to be responsive to other tasks while that task is still running instead of waiting for the completion.
With asynchronous programming, HTTP requests actions or user selection can take a lot of time, and therefore, it would be intelligent to allow other tasks to run while such actions are still being done.
In Python, to achieve asynchronous programming, you can use the
async/await features with functions, but we do such with
lambda functions. This article will discuss the possibility of using
await in a Python lambda function.
async/await lambda in a Python Lamda
To carry out asynchronous programming in Python, we need a built-in high-level package called
asyncio that uses the
async/await syntax to allow for concurrent programming.
To create an asynchronous operation, you can use the
import asyncio async def main(): print("Action One") await asyncio.sleep(1) print("Action Two") asyncio.run(main())
Action One Action Two
We applied the
async keyword to the
main() function and the
await keyword on the
asyncio.sleep() statement; however, how do we apply it to an anonymous function via
lambda? Anonymous or
lambda functions are defined without a name and use the
lambda keyword to achieve that.
Say you want to remove from your list the numbers that are not divisible by 3. We can use the
filter() method (a higher-order function) that takes another function.
So instead of defining a function binding that you might not use again, you can use an anonymous function using the
myNums = [1, 2, 3, 4, 5, 6, 7] myNums = list(filter(lambda x: x%3 == 0, myNums)) print(myNums)
However, is there a way to add the asynchronous capabilities to the
lambda function? The simple answer is No.
The developers of Python have stated that there are no significant use cases to justify adding the
async syntax for
Also, the naming of
lambda isn’t the proper use of
lambda functions; therefore, it would be hard to use it functionally with
lambda functions. In addition, passing an
async function via a
lambda function will be executed within a synchronous function.
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