Clean xml ==> Remove line if any empty tags

Question

I would like to clean up my xml so that not only is it valid XML, but it is formatted in a very human readable way. For example:

<Items>
    <Name>Hello</Name>
    <Cost>9.99</Cost>
    <Condition/>
</Items>

I would like to remove any lines with an empty tag, leaving:

<Items>
    <Name>Hello</Name>
    <Cost>9.99</Cost>
</Items>

I tried doing this using a regex, but haven't been having much luck in terms of leaving it in a readable format:

txt = etree.tostring(self.xml_node, pretty_print=True)
txt = re.sub(r'<[a-zA-Z]+/>\n', '', txt)

What would be the best way to accomplish the above?

Answer 1

Use an XML parser.

The idea is to find all empty nodes with //*[not(node())] XPath expression and remove them from the tree. Example, using lxml:

from lxml import etree


data = """
<Items>
    <Name>Hello</Name>
    <Cost>9.99</Cost>
    <Condition/>
</Items>
"""

root = etree.fromstring(data)
for element in root.xpath(".//*[not(node())]"):
    element.getparent().remove(element)

print etree.tostring(root, pretty_print=True)