python - 使用 for 循环 append 到列表时出现 MemoryError

Question

def show_magicians(magicians_list):
    """Print the name of each magician in a list."""
    for magician in magicians_list:
        print(magician.title())

def make_great(magicians_list):
    """Make each magician great again."""
    for magician in magicians_list:
        magician = magician + " " + "the Great"
        magicians_list.append(magician)

list_of_dudes = ['houdini','david blaine','jebus']

make_great(list_of_dudes)

show_magicians(list_of_dudes)

print(list_of_dudes)

为什么第二个功能不起作用？我试图将名单中的每个魔术师更改为“[魔术师]伟大”，但我不断收到内存错误。有什么建议吗？

谢谢你，-困惑的n00b

Answer 1

您不应该追加到列表中，您应该将每个元素替换为其“伟大”版本。

def make_great(magicians_list):
    """Make each magician great again."""
    for i, magician in enumerate(magicians_list):
        magician = magician + " " + "the Great"
        magicians_list[i] = magician

您的版本将 append 到它正在迭代的列表中。结果，它永远不会结束，因为它继续迭代新元素，并使它们变得更大 (houdini the Great the Great)，然后迭代这些元素 (houdini the Great the Great) Great the Great)等等，直到内存耗尽。