python - Can ElementTree be told to preserve the order of attributes? -

i've written simple filter in python using elementtree munge contexts of xml files. , works, more or less.

but reorders attributes of various tags, , i'd not that.

does know switch can throw make keep them in specified order?

context this

i'm working , on particle physics tool has complex, oddly limited configuration system based on xml files. among many things setup way paths various static data files. these paths hardcoded existing xml , there no facilities setting or varying them based on environment variables, , in our local installation in different place.

this isn't disaster because combined source- , build-control tool we're using allows shadow files local copies. thought data fields static xml isn't, i've written script fixing paths, attribute rearrangement diffs between local , master versions harder read necessary.

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this first time taking elementtree spin (and fifth or sixth python project) maybe i'm doing wrong.

abstracted simplicity code looks this:

tree = elementtree.elementtree.parse(inputfile) = tree.getiterator() e in i:     e.text = filter(e.text) tree.write(outputfile) 

reasonable or dumb?

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related links:

• how can order of element attribute list using python xml.sax?
• preserve order of attributes when modifying minidom

with @bobince's answer , these 2 (setting attribute order, overriding module methods)

i managed monkey patched it's dirty , i'd suggest using module better handles scenario when isn't possibility:

# ======================================================================= # monkey patch elementtree import xml.etree.elementtree et  def _serialize_xml(write, elem, encoding, qnames, namespaces):     tag = elem.tag     text = elem.text     if tag et.comment:         write("<!--%s-->" % et._encode(text, encoding))     elif tag et.processinginstruction:         write("<?%s?>" % et._encode(text, encoding))     else:         tag = qnames[tag]         if tag none:             if text:                 write(et._escape_cdata(text, encoding))             e in elem:                 _serialize_xml(write, e, encoding, qnames, none)         else:             write("<" + tag)             items = elem.items()             if items or namespaces:                 if namespaces:                     v, k in sorted(namespaces.items(),                                        key=lambda x: x[1]):  # sort on prefix                         if k:                             k = ":" + k                         write(" xmlns%s=\"%s\"" % (                             k.encode(encoding),                             et._escape_attrib(v, encoding)                             ))                 #for k, v in sorted(items):  # lexical order                 k, v in items: # monkey patch                     if isinstance(k, et.qname):                         k = k.text                     if isinstance(v, et.qname):                         v = qnames[v.text]                     else:                         v = et._escape_attrib(v, encoding)                     write(" %s=\"%s\"" % (qnames[k], v))             if text or len(elem):                 write(">")                 if text:                     write(et._escape_cdata(text, encoding))                 e in elem:                     _serialize_xml(write, e, encoding, qnames, none)                 write("</" + tag + ">")             else:                 write(" />")     if elem.tail:         write(et._escape_cdata(elem.tail, encoding))  et._serialize_xml = _serialize_xml  collections import ordereddict  class orderedxmltreebuilder(et.xmltreebuilder):     def _start_list(self, tag, attrib_in):         fixname = self._fixname         tag = fixname(tag)         attrib = ordereddict()         if attrib_in:             in range(0, len(attrib_in), 2):                 attrib[fixname(attrib_in[i])] = self._fixtext(attrib_in[i+1])         return self._target.start(tag, attrib)  # ======================================================================= 

then in code:

tree = et.parse(pathtofile, orderedxmltreebuilder())