Python has had async for 10 years – why isn't it more popular?

> lambdas only permitting a single expression

Use a tuple, maybe walrus, and return the last item[-1].

That idea sounds good.

How do I get variables for not redoing long-running computations that depend on one-another? So, what if the third tuple value depends on the second and the second in turn depends on the first?

You can abuse list and sequence comprehensions for this. `for..in` is effectively a variable binding since you can target a freshly created list or a tuple if you need to bind a single value. So:

  [x
   for x in [some_complicated_expression]
   if x > 0
   for y in [x + 1]
   ...
  ][0]

That said, I wouldn't recommend this because of poor readability.

That’s what walrus is for:

    future = lambda age: (
        print('Your age is:', age),
        older := age + 5,
        print('Your age in the future:', older),
        older,
    )[-1]

    print(future(20))

    # out
    Your age is: 20
    Your age in the future: 25
    25