python: retaining xml formatting using etree

Question

I'm using lxml etree to format xml and modify some values. Here's a snippet of the input XML

        <FIELD
            NAME="A"
            SHORT_DESCRIPTION="AAAAA"
            OFFSET="0"
            WIDTH="0"
        >       </FIELD>

        <FIELD
            NAME="B"
            SHORT_DESCRIPTION="BBBBBB"
            OFFSET="1"
            WIDTH="1"
        >       </FIELD>

code:

        from lxml import etree as ET
        tree = ET.parse(path)
        root = tree.getroot()
        #read and modify attributes
        tree.write('output.xml', pretty_print=True)

But the output is of the form:

 <FIELD NAME="A" SHORT_DESCRIPTION="AAAAA" OFFSET="100" WIDTH="0"> </FIELD>

I tried converting it into a string and then using etree but I get the same results.

I expect it to be in the same format as the XML was originally with the attributes across several lines.

How are you opening the XML? If you open the file using VScode or another editor as an XML it will format it in the way that you want — Edeki Okoh, Sep 19 '19 at 23:33
I'm using vim; but the issue is that others would want the XML to be open in human readable form using emacs or vi. — aravi, Sep 19 '19 at 23:36
Possible duplicate of [Vim indent xml file](https://stackoverflow.com/questions/21408222/vim-indent-xml-file) — Edeki Okoh, Sep 19 '19 at 23:38
It's more of vim doing its job before I run my script and the script merges all attributes to a single line. — aravi, Sep 19 '19 at 23:41

score 0 · Answer 1 · answered Sep 20 '19 at 00:32

Here is an example of reading, modifying & writing and XML file using lxml:

PS: Your XML input is not valid, you need to wrap it in a parend tag

input.xml

<items>
<FIELD NAME="A" SHORT_DESCRIPTION="AAAAA" OFFSET="0" WIDTH="0"></FIELD>
<FIELD NAME="B" SHORT_DESCRIPTION="BBBBBB" OFFSET="1" WIDTH="1"></FIELD>
</items>

modify_xml.py

from lxml import etree as ET


tree = ET.parse('input.xml')
root = tree.getroot()
# find all fields in the given root
fields = root.iterfind('.//FIELD')
# Example of modifying text and attributes of fields
for field in fields:
    if field.get('OFFSET') == '0':
        field.set('SHORT_DESCRIPTION', 'aaaa')
        field.text = 'TEST 0'
    else:
        field.set('SHORT_DESCRIPTION', 'bbbb')
        field.text = 'TEST 1'

tree.write('output.xml')

output.xml

<items>
<FIELD NAME="A" SHORT_DESCRIPTION="aaaa" OFFSET="0" WIDTH="0">TEST 0</FIELD>
<FIELD NAME="B" SHORT_DESCRIPTION="bbbb" OFFSET="1" WIDTH="1">TEST 1</FIELD>
</items>

python: retaining xml formatting using etree

1 Answers1