Question

我在python中有一个函数，就像find命令一样。所以基本上它会深入到m_depth （maxdepth），如果在ignore_dirs中指定，它将不会进入目录。它将返回walk中找到的文件列表。代码非常简单并使用递归。

但是对于大量文件或更大的深度，递归花费时间并且返回时列表变得越来越大。所以无论如何我都在寻找发生器，所以至少每次迭代的内存消耗都会减少？

我尝试使用yield结果，但只要找到ignore_dirs就会退出。

这是我的代码：

def find(source_d, m_depth, ignore_dirs):
    '''
    This method does a recursive listing of files/directories from a given 
    path upto maximun recursion value provide as m_depth.

    :param source_d: Given source path to start the recursion from
    :param m_depth: Maximum recursion depth [determines how deep the method will traverse through the file system]
    :param ignore_dirs: this paths will not be traversed. List of strings. 
    '''

    def helper_find(path, ignore_dirs, m_depth, curr_depth=1):
        files = []
        if any(ignore_sub_dir == os.path.split(path)[-1] for ignore_sub_dir in ignore_dirs):
            return []

        if m_depth < curr_depth:
            return []

        else:
            things = os.listdir(path)

            for thing in things:
                if(os.path.isdir(os.path.join(path, thing))):
                    files.extend(helper_find(os.path.join(path, thing), ignore_dirs, m_depth, curr_depth+1))

                else:
                    files.append(os.path.join(path, thing))

        return files

    return helper_find(source_d, ignore_dirs, m_depth)

Answer 1

答案是肯定的，你可以使用yield from制作一个递归生成器（仅在Python 3中可用）：

def find(source_d, m_depth, ignore_dirs):
    '''
    This method does a recursive listing of files/directories from a given
    path upto maximun recursion value provide as m_depth.

    :param source_d: Given source path to start the recursion from
    :param m_depth: Maximum recursion depth [determines how deep the method will traverse through the file system]
    :param ignore_dirs: this paths will not be traversed. List of strings.
    '''
    def helper_find(path, ignore_dirs, m_depth, curr_depth=1):
        if not any(ignore_sub_dir == os.path.split(path)[-1] for ignore_sub_dir in ignore_dirs)and m_depth >= curr_depth:

            things = os.listdir(path)

            for thing in things:
                if(os.path.isdir(os.path.join(path, thing))):
                    yield from helper_find(os.path.join(path, thing), ignore_dirs, m_depth, curr_depth+1)

                else:
                    yield os.path.join(path, thing)

    return helper_find(source_d, ignore_dirs, m_depth)

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1 个答案: