2-state 3-symbol State Machine with Two Stacks and One Cell, same as Wolfram's (2,3) Universal Turing Machine

w23tm-2stacksLCR.py

from time import sleep

# (state,symbol) => (state,symbol,head)
delta = {(0,0):(1,1,+1), (0,1):(0,2,-1), (0,2):(0,1,-1),
         (1,0):(0,2,-1), (1,1):(1,2,+1), (1,2):(0,0,+1)}
ds = {0: ' ', 1: '.', 2: '*'}

state, stackL, C, stackR = 0, [0]*29, 0, [0]*50

while len(stackL) > 0 and len(stackR) > 0:
    state, C, head = delta[(state,C)]
    if head == +1:
        stackL.insert(0, C)
        C = stackR[0]; stackR = stackR[1:]
    else:
        stackR.insert(0, C)
        C = stackL[0]; stackL = stackL[1:]
    for s in list(reversed(stackL))+[C]+stackR : print(ds[s], end='')
    print()
    sleep(0.005)