How to display XML tree structure with Python?

[sonicblind]

Hi,

I have a large multi-level XML document of a complicated structure, without any namespace definition.
I would like to generate a simplified tree view of its structure, so that every possible element from the XML is shown and only once.

As a simplified example take this XML:

<data>
	<timestamp>...</timestamp>
	<people>
		<person>
			<name>...</name>
			<age>...</age>
		</person>
		<person>
			<name>...</name>
			<age>...</age>
			<degree />
		</person>
		<person>
			<name>...</name>
			<age>...</age>
			<degree />
			<siblings>
				<brother>...</brother>
				<brother>...</brother>
				<sister>...</sister>
			</siblings>			
		</person>
	</people>
	<cities>
		<city>
			<name>...</name>
			<country>...</country>
			<continent>...</continent>
			<capital />
		</city>
		<city>
			<name>...</name>
			<country>...</country>
			<continent>...</continent>
		</city>
	</cities>
</data>

Using Python I would like to generate a view of its structure, looking something like this:

-data-
	-timestamp-
	-people-
		-person-
			-name-
			-age-
			-degree-
			-siblings-
				-brother-
				-sister-
	-cities-
		-city-
			-name-
			-country-
			-continent-
			-capital-

So, basically I am not interested in the values, or how many elements of the same type are in the XML, etc.
I only want to see which elements are in there.

I know there might be visual tools to achieve this, but I need to be able to generate such tree view also directly inside python script.

Thanks for any ideas.