Build unordered list in HTML from a python list

[Nico Grubert]

Dear list members

I have this python list that represets a sitemap:

tree = [{'indent': 1, 'title':'Item 1', 'hassubfolder':False},
         {'indent': 1, 'title':'Item 2', 'hassubfolder':False},
         {'indent': 1, 'title':'Folder 1', 'hassubfolder':True},
         {'indent': 2, 'title':'Sub Item 1.1', 'hassubfolder':False},
         {'indent': 2, 'title':'Sub Item 1.2', 'hassubfolder':False},
         {'indent': 1, 'title':'Item 3', 'hassubfolder':False},
         {'indent': 1, 'title':'Folder 2', 'hassubfolder':True},
         {'indent': 2, 'title':'Sub Item 2.1', 'hassubfolder':False},
         {'indent': 2, 'title':'Folder 2.1', 'hassubfolder':True},
         {'indent': 3, 'title':'Sub Item 2.1.1', 'hassubfolder':False},
         {'indent': 3, 'title':'Sub Item 2.1.2', 'hassubfolder':False},
        ]

 From that list I want to create the following HTML code:

<ul id="tree">
   <li>Item 1</li>
   <li>Item 2</li>
   <li>Folder 1
     <ul>
       <li>Sub Item 1.1</li>
       <li>Sub Item 1.2</li>
     </ul>
   </li>
   <li>Item 3</li>
   <li>Folder 2
     <ul>
       <li>Sub Item 2.1</li>
       <li>Folder 2.1
         <ul>
           <li>Sub Item 2.1.1</li>
           <li>Sub Item 2.1.2</li>
         </ul>
       </li>
     </ul>
   </li>
</ul>

If an item of the list has 'True' for the 'hassubfolder' key than a new 
"<ul><li>" must be created instead of "</li>" after its title. (See 
"Folder 2" node in the HTML code above.

My problem is: How do I keep track of the closing tags while iterating 
over the python list?

Any help is much appreciated.

Regards
Nico