robot_golf_1.py

from gpiozero import RyanteckRobot, Button
from signal import pause

robot = RyanteckRobot()

button_actions = {
    Button(26): robot.forward,
    Button(16): robot.left,
    Button(21): robot.right,
    Button(20): robot.backward,
}

for btn, action in button_actions.items():
    btn.when_pressed = action
    btn.when_released = robot.stop

pause()

robot_golf_2.py

from gpiozero import RyanteckRobot as R, Button as B
from signal import pause

r = R()

a = {
    B(26): r.forward,
    B(16): r.left,
    B(21): r.right,
    B(20): r.backward,
    }

for b, m in button_actions.items():
    b.when_pressed = m
    b.when_released = r.stop

pause()

robot_golf_3.py

# When the going gets weird, the weird turn pro...

from gpiozero import RyanteckRobot as R, Button as B
from signal import pause

r = R()
s = setattr
x = lambda b, m: (b, s(b, 'when_pressed', m), s(b, 'when_released', r.stop))[0]
l = [x(B(p), m) for p, m in {
    26: r.forward,
    16: r.left,
    21: r.right,
    20: r.backward,
    }.items()]

pause()

robot_golf_4.py

# For the truly bloody minded...

from gpiozero import RyanteckRobot as R, Button as B
from signal import pause

l = [
    (lambda b, m: (
        b,
        setattr(b, 'when_pressed', m),
        setattr(b, 'when_released', r.stop)
        )[0])
        (B(p), m)
    for r in (R(),)
    for p, m in (
        (26, r.forward),
        (16, r.left),
        (21, r.right),
        (20, r.backward),
        )]

pause()

robot_golf_5.py

# Help

from gpiozero import RyanteckRobot as R, Button as B
from signal import pause

l = [
    (b, s(b, 'when_pressed', m), s(b, 'when_released', r.stop))[0]
    for r, s in (R(), setattr)
    for p, m in (
        (26, r.forward),
        (16, r.left),
        (21, r.right),
        (20, r.backward),
        )
    for b in (B(p),)]

pause()

I don't seriously claim that 3 or 4 is in any way better, I was more intrigued whether I could come up with a pure functional method of assigning everything and keeping all the references alive at the end. And yes ... it's truly horrid.

need to make it smaller ;). a valid option would be to modify the class names and function names to 1 character ones, but that might be a bit extreme

I could also remove all the indentations, but there's some things I just can't bring my self to do, not even for golf! ;-)