《Python编程快速上手》Conway's Game of Life代码排查与解析

代码存在的问题 #

这段代码无法正常运行、输出不符合预期的核心原因是Python缩进错误，具体有两处会直接触发运行报错：

• 统计左上角邻居存活状态的if判断分支下，numNeighbors += 1语句没有缩进，和if判断处于同一层级，违反Python缩进规则，直接抛出IndentationError。
• 主循环while True行前存在多余前置空格，和上层初始化代码的缩进层级不匹配，同样会触发缩进报错。

其余代码逻辑本身符合康威生命游戏的规则设计，修正缩进后即可正常运行。

核心代码逻辑解析 #

代码整体采用列优先的二维列表存储网格状态，实现逻辑分为三部分：

• 初始化阶段：定义网格宽度为60、高度为20，随机为每个格子分配初始状态，#代表存活细胞，空格代表死亡细胞。
• 渲染阶段：每轮迭代先打印多个换行分隔前后代画面，深拷贝当前代细胞状态避免计算过程中污染原始数据，按行优先顺序遍历打印网格，输出可视化的细胞状态。
• 演化计算阶段：
  • 用取模运算处理边界坐标，实现环形边界（网格对边相连，不存在越界问题）
  • 统计每个细胞周围8个相邻格子的存活细胞数量
  • 严格按照康威生命游戏规则更新下一代状态：存活细胞周围有2-3个邻居则存活，否则死亡；死亡细胞周围恰好3个邻居则复活，否则保持死亡
  • 每轮演化后暂停1秒，降低画面切换速度方便观察

修正后可运行代码 #

# Conway's Game of Life
import random, time, copy
WIDTH = 60
HEIGHT = 20
# Create a list of list for the cells:
nextCells = []
for x in range(WIDTH):
    column = [] # Create a new column.
    for y in range(HEIGHT):
        if random.randint(0, 1) == 0:
            column.append('#') # Add a living cell.
        else:
            column.append(' ') # Add a dead cell.
    nextCells.append(column) # nextCells is a list of column lists.

while True: # Main program loop.
    print('\n\n\n\n\n') # Separate each step with newlines.
    currentCells = copy.deepcopy(nextCells)
    # Print currentCells on the screen:
    for y in range(HEIGHT):
        for x in range(WIDTH):
            print(currentCells[x][y], end='') # Print the # or space.
        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 neighboring coordinates:
            # `% WIDTH` ensures 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 number of living neighbors:
            numNeighbors = 0
            if currentCells[leftCoord][aboveCoord] == '#':
                numNeighbors += 1 # Top-left neighbor is alive.
            if currentCells[x][aboveCoord] == '#':
                numNeighbors += 1 # Top neighbor is alive.
            if currentCells[rightCoord][aboveCoord] == '#':
                numNeighbors += 1 # Top-right neighbor is alive.
            if currentCells[leftCoord][y] == '#':
                numNeighbors += 1 # Left neighbor is alive.
            if currentCells[rightCoord][y] == '#':
                numNeighbors += 1 # Right neighbor is alive.
            if currentCells[leftCoord][belowCoord] == '#':
                numNeighbors += 1 # Bottom-left neighbor is alive.
            if currentCells[x][belowCoord] == '#':
                numNeighbors += 1 # Bottom neighbor is alive.
            if currentCells[rightCoord][belowCoord] == '#':
                numNeighbors += 1 # Bottom-right neighbor is alive.
            # Set cell based on Conway's Game of Life rules:
            if currentCells[x][y] == '#' and (numNeighbors == 2 or numNeighbors == 3):
                # Living cells with 2 or 3 neighbors stay alive:
                nextCells[x][y] = '#'
            elif currentCells[x][y] == ' ' and numNeighbors == 3:
                # Dead cells with 3 neighbors become alive:
                nextCells[x][y] = '#'
            else:
                # Everything else dies or stays dead:
                nextCells[x][y] = ' '
    time.sleep(1) # Add a 1-second pause to reduce flickering.

内容的提问来源于stack exchange，提问作者Focus 360