I need "get_ancestors_recursively" function.
A sample run can be
>>> dump(tr)
<anc1>
<anc2>
<element> </element>
</anc2>
</anc1>
>>> input_element = tr.getiterator("element")[0]
>>> get_ancestors_recursively(input_element)
['anc1', 'anc2']
Can somebody help me with this ?
In the latest version of ElementTree (v1.3 or later), you can simply do
input_element.find('..')
recursively. However, the ElementTree that ships with Python doesn't have this functionality, and I don't see anything in the Element class that looks upwards.
I believe this means you have to do it the hard way: via an exhaustive search of the element tree.
def get_ancestors_recursively(e, b):
"Finds ancestors of b in the element tree e."
return _get_ancestors_recursively(e.getroot(), b, [])
def _get_ancestors_recursively(s, b, acc):
"Recursive variant. acc is the built-up list of ancestors so far."
if s == b:
return acc
else:
for child in s.getchildren():
newacc = acc[:]
newacc.append(s)
res = _get_ancestors_recursively(child, b, newacc)
if res is not None:
return res
return None
This is slow because of the DFS, and cranks out a lot of lists for garbage collection, but if you can deal with that it should be fine.