Python递归函数缺少结果

Question

来自Python recursively appending list function 尝试递归地获取与文件结构关联的权限列表。你知道吗

我有这个功能：

def get_child_perms(self, folder, request, perm_list):
        # Folder contains other folders
        if folder.get_children():
            # For every sub-folder
            return [self.get_child_perms(subfolder, request, perm_list) for subfolder in folder.get_children()]
        return folder.has_read_permission(request)

返回除包含其他文件夹的文件夹以外的所有结果。你知道吗

folder <- Missing (allowed)
    subfolder <- Missing (restricted)
        subsubfolder <- Get this (restricted)
            files

函数的输出是 [真，假，假]

另一种情况是，A=允许，R=限制

folder  A
    subfolder   A
        subsubfolder    R
            files
        files
    subfolder   R
        files
    subfolder   A
        subsubfolder    A
            files
        files
    subfolder   A
        files
    files

输出将是 [真，真，假，假，真，真，真，真]

Answer 1

为什么不 os.walk

When topdown is True, the caller can modify the dirnames list in-place (perhaps using del or slice assignment), and walk() will only recurse into the subdirectories whose names remain in dirnames; this can be used to prune the search, impose a specific order of visiting, or even to inform walk() about directories the caller creates or renames before it resumes walk() again. Modifying dirnames when topdown is False is ineffective, because in bottom-up mode the directories in dirnames are generated before dirpath itself is generated.

例如，您可以构建只生成非限制目录的生成器（惰性列表）

for (dirpath, dirnames, filenames) in os.walk("top_path"):
    if restricted(dirpath):
        del dirnames
        continue
    yield (dirpath,tuple(filenames))