python – lxml: enforcing a specific order for attributes

by

It looks like lxml serializes attributes in the order you set them:

>>> from lxml import etree as ET
>>> x = ET.Element("x")
>>> x.set('a', '1')
>>> x.set('b', '2')
>>> ET.tostring(x)
'<x a="1" b="2"/>'
>>> y= ET.Element("y")
>>> y.set('b', '2')
>>> y.set('a', '1')
>>> ET.tostring(y)
'<y b="2" a="1"/>'

Note that when you pass attributes using the ET.SubElement() constructor, Python constructs a dictionary of keyword arguments and passes that dictionary to lxml. This loses any ordering you had in the source file, since Python’s dictionaries are unordered (or, rather, their order is determined by string hash values, which may differ from platform to platform or, in fact, from execution to execution).

More Related Contents:

  1. Using Python Iterparse For Large XML Files
  2. how to remove an element in lxml
  3. How can this function be rewritten to implement OrderedDict? [duplicate]
  4. Remove namespace and prefix from xml in python using lxml
  5. using lxml and iterparse() to parse a big (+- 1Gb) XML file
  6. How do I use a default namespace in an lxml xpath query?
  7. parsing xml containing default namespace to get an element value using lxml
  8. Parse SGML with Open Arbitrary Tags in Python 3
  9. parsing XML file gets UnicodeEncodeError (ElementTree) / ValueError (lxml)
  10. How to include the namespaces into a xml file using lxml?
  11. Why does this xpath fail using lxml in python?
  12. Pretty print in lxml is failing when I add tags to a parsed tree
  13. Why doesn’t xpath work when processing an XHTML document with lxml (in python)?
  14. Why is lxml.etree.iterparse() eating up all my memory?
  15. Parsing broken XML with lxml.etree.iterparse
  16. lxml: add namespace to input file
  17. Creating a simple XML file using python
  18. Error while installing lxml through pip: Microsoft Visual C++ 14.0 is required
  19. How can I create a Word document using Python? [closed]
  20. How to update/modify an XML file in python?
  21. Using XPath in ElementTree
  22. How to write XML declaration using xml.etree.ElementTree
  23. Faithfully Preserve Comments in Parsed XML
  24. Extracting lxml xpath for html table
  25. inserting newlines in xml file generated via xml.etree.ElementTree in python
  26. Python: Using xpath locally / on a specific element
  27. Installing lxml, libxml2, libxslt on Windows 8.1
  28. Installing lxml for Python 3.4 on Windows x 86 (32 bit) with Visual Studio C++ 2010 Express
  29. Beautiful Soup and Table Scraping – lxml vs html parser
  30. Emitting namespace specifications with ElementTree in Python

Leave a Comment