function returns multiple values, assignment to tuples with different number of entries?

Question

A Python-function foo(p, q) calculates four values a, b, c, and returns

return a, b, c, d

In the calling function I need an assignment like

(r, s, t, u) = (p, q, foo(p, q))

or

((r, s), (t, u)) = ((p, q), foo(p, q))

How does the code look like?

Something like r, s, t, u, *_ = (p, q) + foo(p, q) would also work if you don't care about c and d that's being returned. — Axe319
– Axe319, Commented Jul 1, 2022 at 17:44
Optionally, you could use r, s, (*_, t, u) = (p, q, foo(p, q)) to discard a and b. — Axe319
– Axe319, Commented Jul 1, 2022 at 17:54

Barmar · Accepted Answer · 2022-07-01 19:45:54Z

2

The structure of the receivers should be the same as what's being assigned and returned.

r, s, (w, x, y, z) = p, q, foo(p, q)

If you only want the last two elements of the foo(p, q) respnse you can slice it:

r, s, (w, x) = p, q, foo(p, q)[2:]

or use * in the assignment:

r, s, (*_, w, x) = p, q, foo(p, q)

answered Jul 1, 2022 at 17:39

Barmar

789k57 gold badges554 silver badges669 bronze badges

Sign up to request clarification or add additional context in comments.

1 Answer 1