How To Add Line Numbers To A Docx Document Section Using Python-docx

I am using python-docx to generate some documents. I can see that there exists a line numbering property which may be applied to document sections (for the OOXML standard at least)

Solution 1:

Once you have the Section object, you can get the sectPr element with:

sectPr = section._sectPr

If you Google on 'python-docx workaround function OxmlElement' you'll find examples. All elements inherit from lxml _Element so lxml manipulation works. There are also some handy other methods added by BaseOxmlElement. A basic gist would be:

sectPr = section._sectPr
lnNumType = OxmlElement('w:lnNumType')
lnNumType.set('fooAttrib', '42')
sectPr.append(lnNumType)

In many cases you'll need to attend to getting any new child elements in the right order, as the sequence is almost always prescribed.

You can find some handy analysis of the w:sectPr element here: http://python-docx.readthedocs.io/en/latest/dev/analysis/features/sections.html

It looks from a quick glance that you'll be able to just append a w:lnNumType on the end as the elements that follow it are less common. But if you wanted to be more rigorous you could use this instead of sectPr.append():

sectPr.insert_element_before(lnNumType, (
    'w:pgNumType', 'w:pgNumType', 'w:cols', 'w:formProt', 'w:vAlign',
    'w:noEndnote', 'w:titlePg', 'w:textDirection', 'w:bidi',
    'w:rtlGutter', 'w:docGrid', 'w:printerSettings', 'w:sectPrChange',
))

You can see the implementation for .insert_element_before() here: https://github.com/python-openxml/python-docx/blob/master/docx/oxml/xmlchemy.py#L718