conway.py

from time import sleep
from random import random

def main():
    printIntro()
    rows, cols, gens = getInputs()
    thisGen = initGame(rows, cols)
    nextGen = initGame(rows, cols)
    for gen in range(gens): #I meant to have it clear the screen each time
        printGen(rows, cols, thisGen) # but I couldn't get os.system('cls')
        calcNext(rows, cols, thisGen, nextGen) #to work right.
        thisGen = nextGen[:]
        sleep(.1)
        print()
    if input("Type 'again' to try again.  <return> to close. ") == "again":
        main()


def printIntro():
    print("Conway's Game of Life")
    print()
    print("Conway's Game of Life is a cellular automaton.")
    print("There's a grid of cells that act according to rules.")
    print("If a cell is alive and has 2 or 3 neighbors (in the surrounding 8) it survives.")
    print("If a cell is dead and has 3 neighbors it lives.")
    print("All other cells are dead or die.")
    print()

def getInputs():
    try:
        rows = eval(input("How many rows tall? 'return' for 20 "))
    except SyntaxError:
        rows = 20
    try:
        cols = eval(input("How many columns wide? 'return' for 40 "))
    except SyntaxError:
        cols = 40
    try:
        gens = eval(input("How many generations would you like to simulate? 'return' for 100 "))
    except SyntaxError:
        gens = 100
    return rows, cols, gens

def initGame(rows, cols): # makes a randomized grid
    array = []
    for r in range(rows):
        row = []
        for c in range(cols):
            if (r == 0 or c == 0 or r == rows - 1 or c == cols - 1):
                row += [-1] #establish a boundary that won't change
            else:
                rand = random()
                if rand < .33:
                    row += [1]
                else:
                    row += [0]
        array.append(row)
    return array

def printGen(rows, cols, thisGen):

    for r in range(rows):
        for c in range(cols):
            if r ==(0 or rows - 1):
                print("-", end="") # top and bottom boundary
            elif c ==(0):
                print("|", end="") # left boundary
            elif c == (cols - 1):
                print("|") #different line so it'd end with \n
            elif thisGen[r][c] == 1:
                print("█", end="")
            else:
                print("░", end="") # because I wanted more than just a " "


def calcNext(rows, cols, thisGen, nextGen):
    for r in range(1, rows - 1):
        for c in range(1, cols-1):
            nextGen[r][c] = getState(r, c, thisGen)

def getState(x, y, gen):
    count = 0 #number of neighbors
    for r in range(x-1, x+2):
        for c in range(y-1, y + 2):
            if gen[r][c] != -1:
                count += gen[r][c]
    if count == 3:
        return 1
    elif count == 4:
        return gen[x][y]
    else:
        return 0
    # I got this idea from the wikipedia page for Conway's Game of Life, under "algorithms"




if __name__ == "__main__":
    main()