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

Question

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 ?

Might be worth removing that bare `except` there in case you're silently swallowing errors... — Jon Clements, Jul 03 '19 at 13:00
@JonClements Updated the question, although it doesn't really make any difference!! — Virat, Jul 03 '19 at 13:09

score 1 · Accepted Answer · answered Jul 03 '19 at 13:31

Your function returns None in case of some exception. Using block try: except you are catching any exception, so you can't face the reason of the problem, try to remove this block from code to see the problem, or catch more specific exception. And as I see 'folderstructure' has no name, you can fix this by adding <folderstructure name='some name'> in your xml or set default name for your root element. code below seems working:

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

        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}

Altering the way I use try-catch really helped. Your solution was elegant! I extended it to my use case, without having to add `name` attribute!! Thanks!! — Virat, Jul 03 '19 at 16:09

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

1 Answers1