One dimensional cellular automata with three states

1D_3states_automata.py

#!/usr/bin/env python3

"""
One dimensional cellular automata with three states

If you want to know more about CAs check "A New Kind of Science" by Stephen Wolfram
https://www.wolframscience.com/nks/
"""

### Modules
import string
from random import choice

### Constants
POSSIBLE_SUMS = (6, 5, 4, 3, 2, 1, 0)
DIGITS = string.digits + string.ascii_letters

STATE_2_CHR = {
    0: '⬜',
    1: '🟦',
    2: '⬛'
}

### Functions & Procedures
def makeRuleSet(rule):
    results = f'{int2base(rule, 3):0>7}'
    ruleSet = {k: int(v) for (k, v) in zip(POSSIBLE_SUMS, results)}
    return ruleSet

def applyRules(lft, mid, rgt, ruleSet):
    value = sum([lft, mid, rgt])
    return ruleSet[value]

def printCells(stripe):
    stripeRepr = ''.join([STATE_2_CHR[ii] for ii in stripe])
    print(stripeRepr)

def int2base(x, base):
    """from https://stackoverflow.com/a/2267446"""
    if x < 0:
        sign = -1
    elif x == 0:
        return DIGITS[0]
    else:
        sign = 1

    x *= sign
    digits = []
    while x:
        digits.append(DIGITS[int(x % base)])
        x = int(x / base)

    if sign < 0:
        digits.append('-')

    digits.reverse()
    return ''.join(digits)


### Variables
width = 45
stripes = 45

startWithRandomStripe = False

rule = 101
assert 0 <= rule <= 2186

### Instructions
if __name__ == '__main__':
    if startWithRandomStripe:
        stripe = [choice(STATE_2_CHR.keys()) for _ in range(width)]
    else:
        stripe = [0] * (width-1)
        stripe.insert(width//2, 2)

    ruleSet = makeRuleSet(rule)
    printCells(stripe)

    for eachStripe in range(stripes):
        newStripe = []
        for index, mid in enumerate(stripe):
            lft = stripe[(index-1) % len(stripe)]
            rgt = stripe[(index+1) % len(stripe)]
            newCell = applyRules(lft, mid, rgt, ruleSet)
            newStripe.append(newCell)
        stripe = list(newStripe)
        printCells(stripe)