while (value := read_next_item()) is not None:
    ...

results = [(x, y, x/y) for x in input_data if (y := f(x)) > 0]

as

with

[(x, y, x/y) for x in input_data if (f(x) as y) > 0]

[(x, y, x/y) with f(x) as y for x in input_data if y > 0]

[
    (x, y, x/y, z)
    with f(x) as y
    with g(x) as z
    for x in input_data if y > 0
]

where

let

λ let x = 2 in x + 1
3

[ (i,j) | i <- [1..10], let k = i*i, j <- [1..k] ]

import sys
...
SimpleNamespace = type(sys.implementation)

>>> import sys
>>> type(sys.implementation)
<class 'types.SimpleNamespace'>