Getting a list of XML tags in file, using xml.etree.ElementTree

Question

As mentioned, I need to get the list of XML tags in file, using library xml.etree.ElementTree.

I am aware that there are properties and methods like ETVar.child, ETVar.getroot(), ETVar.tag, ETVar.attrib.

But to be able to use them and get at least name of tags on level 2, I had to use nested for.

At the moment I have something like

for xmlChild in xmlRootTag:
    if xmlChild.tag:
        print(xmlChild.tag)

Goal would be to get a list of ALL, even deeply nested XML tags in file, eliminating duplicates.

For a better idea, I add the possible example of XML code:

<root>
 <firstLevel>
  <secondlevel level="2">
    <thirdlevel>
      <fourth>text</fourth>
      <fourth2>text</fourth>
    </thirdlevel>
  </secondlevel>
 </firstlevel>
</root>

Milker

Fantastic D's solution works fine, but there is a closing ) missing: elemList = list(set(elemList)) The order of the elements is neither the order of appearance nor level nor alphabetic. – Souffle

@Souffle Thank you for pointing that out. I updated the answer with your suggestion. Have a nice day! – Milker

Answer 1

I've done more of a research on the subject and found out suitable solution. Since this could be a common task to do, I'll answer it, hence I believe it could help others.

What I was looking for was etree method iter.

import xml.etree.ElementTree as ET
# load and parse the file
xmlTree = ET.parse('myXMLFile.xml')

elemList = []

for elem in xmlTree.iter():
    elemList.append(elem.tag)

# now I remove duplicities - by convertion to set and back to list
elemList = list(set(elemList))

# Just printing out the result
print(elemList)

Important notes

• xml.etree.ElemTree is a standard Python library
• sample is written for Python v3.2.3
• mechanic used to remove duplicities is based on converting to set, which allows only unique values and then converting back to list.

Milker

xmlTree.iter() does not seem to work for Python 2.6.9, I had to switch it to xmlTree.getiterator() – Coper

Answer 2

You could use the built-in Python set comprehension:

import xml.etree.ElementTree as ET

xmlTree = ET.parse('myXMLFile.xml')
tags = {elem.tag for elem in xmlTree.iter()}

If you specifically need a list, you can cast it to a list:

import xml.etree.ElementTree as ET

xmlTree = ET.parse('myXMLFile.xml')
tags = list({elem.tag for elem in xmlTree.iter()})

Ginzburg