Wolfram's 2-state 3-symbol Turing Machine as an Universal TM with Turtle Graphics

w23tm-turtle.py

# Wolfram's 2-state 3-symbol Turing Machine as an Universal TM
# with Turtle Graphics

from time import sleep
from turtle import fd, rt, lt, setpos, pu, pd

pu(); setpos(-300, 300); pd(); sleep(5)

delta = {1: {0: (1,  1, 2), 1: (2, -1, 1), 2: (1, -1, 1)},
         2: {0: (2, -1, 1), 1: (2,  1, 2), 2: (0,  1, 1)}}
tape, head, state = [0] * 30, 10, 1

while 0 <= head < len(tape):
    print(''.join([str(n) for n in tape]))
    t = delta[state][tape[head]]
    tape[head], head, state = t[0], head + t[1], t[2]
    fd(30)
    a = (1 + t[0]) * 45
    if t[1] == 1: rt(a)
    else: lt(a)

print(''.join([str(n) for n in tape])); sleep(5)