I'm extracting the differents files you find in the odt format from the fodt format (content.xml, styles.xml,...) with the xml.dom.minidom library (a Python standard library).
I have modified the ODT parsing method and I still have some errors.
This is the link with modifications and advices from my mentor.
I think I will not continue with the xml.dom.minidom. I will use the lxml library as my mentor recommends me.