Introduction
aiter() is a new function that came in Python 3.10 version. It returns an asynchronous iterator for an asynchronous iterable.
The syntax of the aiter() function looks like this:
aiter(iter)
where iter is an asynchronous iterable.
Examples
When you go look at this page, one of the first examples you will see looks like this the following:
result = [i async for i in aiter() if i % 2]
If you attempt to follow that syntax though, you'll end up with SyntaxError .
$ py main.py
File "C:\Users\ashut\Desktop\Test\Blog-Codes\Built-Ins\aiter\main.py", line 1
result = [i async for i in aiter() if i % 2]
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
SyntaxError: asynchronous comprehension outside of an asynchronous function
To create a real async comprehension, you will need to call another async def function. Let's see an example:
import asyncio
async def numbers(nums):
for i in range(nums):
yield i
await asyncio.sleep(0.5)
async def main():
odd_nums = [i async for i in aiter(numbers(10)) if i % 2 == 0]
print(odd_nums)
if __name__ == " __main__":
event_loop = asyncio.get_event_loop()
try:
event_loop.run_until_complete(main())
finally:
event_loop.close()
When you run this code, you'll get this output:
[0, 2, 4, 6, 8]
In the above code, the numbers() function is an asynchronous generator that is yielding values to our asynchronous list comprehension.
Conclusion
This was a brief introduction to aiter() in Python. You can find more examples here.