Xtykutl

#!/usr/bin/python



def open_doors(state):

    (ld, rd, li, ri, lo, ro, cl, ml, gs) = state



    if not(ld == 0 or rd == 0 or li == 0 or ri == 0 and lo == 0 or ro == 0 or cl == 0 or ml == 0):

      raise ValueError("Error: A state is not specified or invalid entry")



    if not(ld == 1 or rd == 1 or li == 1 or ri == 1 and lo == 1 or ro == 1 or cl == 1 or ml == 1):

      raise ValueError("Error: A state is not specified or invalid entry")



    leftDoor = (ld or li or lo)

    rightDoor = (rd or ri or ro)

    if (li and cl):

      leftDoor = 0

    if (ri and cl):

      rightDoor = 0



    if leftDoor and rightDoor and not ml and gs == 'P':

      print("left door and right door open")

    elif leftDoor and not ml and gs == 'P':

      print("open left door")

    elif rightDoor and not ml and gs == 'P':

      print("open right door")

    else:

      print("both doors stay closed")   



open_doors([0,0,1,6,0,0,1,0,'2'])

Raises ValueError if not every state is specified,
the switches and locks are not 0 or 1 or the gs is
not one of ('P' 'R', 'N', '2', '3' 'D')

I would do

if any((i != 0 and i != 1) for i in state):

  raise ValueError("Error: A state is not specified or invalid entry")

This is short and concise.

It can be even changed to

valid = set((0, 1))

if any(i not in valid for i in state):

  raise ValueError("Error: A state is not specified or invalid entry")

bit I am not sure if that is better performance- or readability-wise.