合并一些维护重复值的字典，但在Python中合并重复的键

Question

我的合并词典代码出错了。这就是我得到的：

output1 = {'children': 
                    {'children':
                              {'children': 
                                        {'name': 'thriller.mp3', 'type': 'file'},
                               'name': 'pop',
                               'type': 'folder'},
                     'name': 'test_pendrive',
                     'type': 'folder'},
           'name': 'media',
           'type': 'folder'}
output2 = {'children': 
                    {'children':
                              {'children': 
                                        {'name': 'paranoid.mp3', 'type': 'file'},
                               'name': 'metal',
                               'type': 'folder'},
                     'name': 'test_pendrive',
                     'type': 'folder'},
           'name': 'media',
           'type': 'folder'}

我的代码目前看起来像这样：

from collections import defaultdict

l1 = list(output2.items())
l2 = list(output.items())

l3 = l1+l2
d1 = defaultdict(list)
for k,v in l3:
   d1[k].append(v)

给出了输出：

{
    "name": ["media", "media"],
    "type": ["folder", "folder"],
    "children": [{
            "name": "test_pendrive",
            "type": "folder",
            "children": {
                "name": "dance",
                "type": "folder",
                "children": {
                    "name": "billie_jean.mp3",
                    "type": "file"
                }
            }
        },
        {
            "name": "test_pendrive",
            "type": "folder",
            "children": {
                "name": "pop",
                "type": "folder",
                "children": {
                    "name": "thriller.mp3",
                    "type": "file"
                }
            }
        }
    ]
}

这几乎就是我想要的。我的最终目标是：

{
    "name": ["media", "media"],
    "type": ["folder", "folder"],
    "children": [{
            "name": "test_pendrive",
            "type": "folder",
            "children": [{
                "name": "dance",
                "type": "folder",
                "children": {
                    "name": "billie_jean.mp3",
                    "type": "file"
                }
            },{
                "name": "pop",
                "type": "folder",
                "children": {
                    "name": "thriller.mp3",
                    "type": "file"
                }
            }]
      }
}

我哪里错了？这是实现这一目标的最佳方法吗？提前致谢。