目前用 Python自動化的樂趣 這本書寫到 Conway's game of life 問題
以下是書中的解答

def conway_game_of_life1():
    import random, time, copy
    WIDTH  = 30
    HEIGHT = 10
        
    # Create a list of list for the cell
    nextCells = []
    for x in range(WIDTH):
        column = []    # Create a new column
        for y in range(HEIGHT):
            if random.randint(0, 1) == 0:
                column.append('#')
            else:
                column.append(' ')
        nextCells.append(column)        
    
    while True :    # This is Main loop.   
        print('\n\n\n\n\n')    # Separate each step with newlines.
        currentCwlls = copy.deepcopy(nextCells)
    
        # Print currentCells on the screen :
        for y in range(HEIGHT):
            for x in range(WIDTH):
                print(currentCwlls[x][y], end = '')    # Print the 0 or 1.
            print()    # Print a newline at the end of the row.    
    
        # Calculate the next step's cells based on current step's cells :
        for x in range(WIDTH):
            for y in range(HEIGHT):
                # Get neigboring coordinates:
                # use " % WIDTH " can ensure leftCoord is always between 0 and WIDTH - 1.
                leftCoord  = (x - 1) % WIDTH
                rightCoord = (x + 1) % WIDTH
                aboveCoord = (y - 1) % HEIGHT
                belowCoord = (y + 1) % HEIGHT
            
                # Count the number of living neighbors:
                numNeighbors = 0
                **# 在下一行出錯**
                if currentCwlls[leftCoord][aboveCoord] == '#' :
                    numNeighbors += 1
                if currentCwlls[x][aboveCoord] == '#' :
                    numNeighbors += 1    
                if currentCwlls[rightCoord][aboveCoord] == '#' :
                    numNeighbors += 1                
                if currentCwlls[rightCoord][y] == '#' :
                    numNeighbors += 1                                
                if currentCwlls[leftCoord][y] == '#' :
                    numNeighbors += 1
                if currentCwlls[rightCoord][belowCoord] == '#' :
                    numNeighbors += 1
                if currentCwlls[x][belowCoord] == '#' :
                    numNeighbors += 1 
                if currentCwlls[leftCoord][belowCoord] == '#' :
                    numNeighbors += 1    
                                        
                                        
                # Set cell based on Conway's Game of Life rules:
                if currentCwlls[x][y] == 1 and (numNeighbors == 2 or numNeighbors == 3) :
                    nextCells[x][y] = '#'
                elif currentCwlls[x][y] == 0 and numNeighbors == 3 :
                    nextCells[x][y] = '#'
                else:
                    currentCwlls = ' '
                
        time.sleep(1)

但是出現了 string index out of range 這個錯誤
請問如何更改呢 (我用的是Anaconda的Spyder)