switch_3_pos.py

import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BCM)

top_input = 18
bottom_input = 23

GPIO.setup(top_input, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setup(bottom_input, GPIO.IN, pull_up_down=GPIO.PUD_UP)

switch_position = "unknown"

while True:
    top_state = GPIO.input(top_input)
    bottom_state = GPIO.input(bottom_input)
    new_switch_position = "unknown"
    if top_state == False:
        new_switch_position = "up"
    elif bottom_state == False:
        new_switch_position = "down"
    else:
        new_switch_position = "center"
    if new_switch_position != switch_position:
        switch_position = new_switch_position
        print(switch_position)