Python递归函数缺少结果

Question

来自Python recursively appending list function尝试以递归方式获取与文件结构关联的权限列表。

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)

这将返回除包含其他文件夹的文件夹之外的所有结果。

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

函数的输出是[对，错，错]

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]

Answer 1

基本问题发生，您只返回文件夹权限，当文件夹没有任何子项时，当它有子项时，您不包括folder.has_read_permission(request) 在您的返回结果中，这很可能导致您出现问题。你需要做 -

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

这应该导致(未测试)-

[folderperm [subfolderperm [subsubfolderperm]]

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