Larry Martell, 26.11.2013 13:23: > On Tue, Nov 26, 2013 at 2:38 AM, Stefan Behnel wrote: >> larry.martell...@gmail.com, 25.11.2013 23:22: >>> I have an XML file that has an element called "Node". These can be nested >>> to any depth and the depth of the nesting is not known to me. I need to >>> parse the file and preserve the nesting. For exmaple, if the XML file had: >>> >>> <Node Name="A"> >>> <Node Name="B"> >>> <Node Name="C"> >>> <Node Name="D"> >>> <Node Name="E"> >>> >>> When I'm parsing Node "E" I need to know I'm in A/B/C/D/E. Problem is I >>> don't know how deep this can be. This is the code I have so far: >>> >>> nodes = [] >>> >>> def parseChild(c): >>> if c.tag == 'Node': >>> if 'Name' in c.attrib: >>> nodes.append(c.attrib['Name']) >>> for c1 in c: >>> parseChild(c1) >>> else: >>> for node in nodes: >>> print node, >>> print c.tag >>> >>> for parent in tree.getiterator(): >>> for child in parent: >>> for x in child: >>> parseChild(x) >> >> This seems hugely redundant. tree.getiterator() already returns a recursive >> iterable, and then, for each nodes in your document, you are running >> recursively over its entire subtree. Meaning that you'll visit each node as >> many times as its depth in the tree. >> >> >>> My problem is that I don't know when I'm done with a node and I should >>> remove a level of nesting. I would think this is a fairly common >>> situation, but I could not find any examples of parsing a file like >>> this. Perhaps I'm going about it completely wrong. >> >> Your recursive traversal function tells you when you're done. If you drop >> the getiterator() bit, reaching the end of parseChild() means that you're >> done with the element and start backing up. So you can simply pass down a >> list of element names that you append() at the beginning of the function >> and pop() at the end, i.e. a stack. That list will then always give you the >> current path from the root node. > > Thanks for the reply. How can I remove getiterator()? Then I won't be > traversing the nodes of the tree. I can't iterate over tree. I am also > unclear on where to do the pop(). I tried putting it just after the > recursive call to parseChild() and I tried putting as the very last > statement in parseChild() - neither one gave the desired result. Can > you show me in code what you mean?
untested: nodes = [] def process_subtree(c, path): name = c.get('Name') if c.tag == 'Node' else None if name: path.append(name) nodes.append('/'.join(path)) for c1 in c: process_subtree(c1, path) if name: path.pop() process_subtree(tree.getroot(), []) Stefan -- https://mail.python.org/mailman/listinfo/python-list