python - 将函数转换为单行列表理解的问题

Question

有人可以向我解释将此函数转换为单行列表理解的正确解决方案吗？

def get_files(directory):
    filepaths = []
    for root, dirs, files in os.walk(directory):
        for filename in files:
           filepaths.append(os.path.join(root, filename))
    return filepath

我已经试过了，但它似乎不起作用(NameError，未定义名称"file")

def get_files(directory):
    return [os.path.join(root, filename) for filename in files for root, dirs, files in os.walk(directory)]

Answer 1

for 语句的顺序错误。尝试:

[os.path.join(root, filename) for root, dirs, files in os.walk(directory)
                              for filename in files]