Python add new element by xml ElementTree

Question

XML file

<?xml version="1.0" encoding="utf-8"?>
<Info xmlns="BuildTest">
<RequestDate>5/4/2020 12:27:46 AM</RequestDate>
</Info>

I want to add a new element inside the Info tag.

Here is what I did.

import xml.etree.ElementTree as ET

tree = ET.parse('example.xml')
root = tree.getroot()
ele = ET.Element('element1')
ele.text = 'ele1'
root.append(ele)
tree.write("output.xhtml")

Output

<ns0:Info xmlns:ns0="BuildTest">
<ns0:RequestDate>5/4/2020 12:27:46 AM</ns0:RequestDate>
<element1>ele1</element1></ns0:Info>

Three questions:

The <?xml version="1.0" encoding="utf-8"?> is missing.
The namespace is wrong.
The whitespace of the new element is gone.

I saw many questions related to this topic, most of them are suggesting other packages. Is there any way it can handle properly?

Amitai Irron · Accepted Answer · 2020-05-07 23:12:39Z

1

The processing instructions are not considered XML elements. Just Google are processing instructions part of an XML, and the first result states:

Processing instructions are markup, but they're not elements.

Since the package you are using is literally called ElementTree, you can reasonably expect its objects to be a trees of elements. If I remember correctly, DOM compliant XML packages can support non-element markup in XML.

For the namespace issue, the answer is in stack overflow, at Remove ns0 from XML - you just have to register the namespace you specified in the top element of your document. The following worked for me:

ET.register_namespace("", "Buildtest")

As for the whitespace - the new element does not have any whitespace. You can assign to the tail member to add a linefeed after an element.

answered May 7, 2020 at 23:12

Amitai Irron

2,1051 gold badge14 silver badges14 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

mzjn Over a year ago

The XML declaration is a special kind of processing instruction that is easily added. Just use tree.write("output.xhtml", xml_declaration=True, encoding="utf-8").

Amitai Irron Over a year ago

@mzjn - thanks, I learned something new. I never bothered with processing instructions, as all my XML usage was always in case where my programs were both the producers and consumers of the XMLs.

Collectives™ on Stack Overflow

Python add new element by xml ElementTree

1 Answer 1

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related