Parsing the root node, to fetch the entire file structure?

My python script reads a XML file, to give the Folder Structure.

My XML file:

<?xml version="1.0" encoding="utf-8"?>
<folderstructure>
  <folder name="Fail">
    <folder name="Cam 1">
      <folder name="Mod1">
        <folder name="2019-04-09" />
      </folder>
    </folder>
    <folder name="Cam 2">
      <folder name="Mod1">
        <folder name="2019-04-09" />
      </folder>
    </folder>
  </folder>
  <folder name="Pass">
    <folder name="Cam 1">
      <folder name="Mod1">
        <folder name="2019-04-09" />
      </folder>
    </folder>
    <folder name="Cam 2">
      <folder name="Mod1">
        <folder name="2019-04-09" />
      </folder>
    </folder>
  </folder>
</folderstructure>

I wrote the following script, with reference to Fetching the path( from root node ) for all the leaf nodes (My previous Question):

def walk(e, runningPath='', flag = 1):
    name = e.attrib['name']

    if len(e)>0:
            runningPath += '/' + name
    children = [walk(c, runningPath, 0) for c in e if ((e.tag == 'folderstructure' and flag==1) or (e.tag=='folder' and flag == 0))]
    print(children)
    return {'name': name, 'children': children} if children else {'name': name, 'path': runningPath + '/' + name}

But the above script yields 'None' as the output.

My desired output is:

{'children': [{'children': [{'children': [{'children': [{'name': '2019-04-09',
                                                         'path': '/Fail/Cam '
                                                                 '1/Mod1/2019-04-09'}],
                                           'name': 'Mod1'}],
                             'name': 'Cam 1'},
                            {'children': [{'children': [{'name': '2019-04-09',
                                                         'path': '/Fail/Cam '
                                                                 '2/Mod1/2019-04-09'}],
                                           'name': 'Mod1'}],
                             'name': 'Cam 2'}],
               'name': 'Fail'},
              {'children': [{'children': [{'children': [{'name': '2019-04-09',
                                                         'path': '/Pass/Cam '
                                                                 '1/Mod1/2019-04-09'}],
                                           'name': 'Mod1'}],
                             'name': 'Cam 1'},
                            {'children': [{'children': [{'name': '2019-04-09',
                                                         'path': '/Pass/Cam '
                                                                 '2/Mod1/2019-04-09'}],
                                           'name': 'Mod1'}],
                             'name': 'Cam 2'}],
               'name': 'Pass'}]
}

How do I go about solving this ?