Creating a simple XML file using python

Question

What are my options if I want to create a simple XML file in python   library wise   The xml I want looks like    lt root gt    lt doc gt        lt field1 name  blah  gt some value1 lt  field1 gt        lt field2 name  asdfasd  gt some vlaue2 lt  field2 gt    lt  doc gt    lt  root gt

User · Answer

The lxml library includes a very convenient syntax for XML generation, called the E-factory. Here's how I'd make the example you give:

#!/usr/bin/python
import lxml.etree
import lxml.builder    

E = lxml.builder.ElementMaker()
ROOT = E.root
DOC = E.doc
FIELD1 = E.field1
FIELD2 = E.field2

the_doc = ROOT(
        DOC(
            FIELD1('some value1', name='blah'),
            FIELD2('some value2', name='asdfasd'),
            )   
        )   

print lxml.etree.tostring(the_doc, pretty_print=True)

Output:

<root>
  <doc>
    <field1 name="blah">some value1</field1>
    <field2 name="asdfasd">some value2</field2>
  </doc>
</root>

It also supports adding to an already-made node, e.g. after the above you could say

the_doc.append(FIELD2('another value again', name='hithere'))

User · Answer

These days  the most popular  and very simple  option is the ElementTree API  which has been included in the standard library since Python 2 5   The available options for that are    ElementTree  Basic  pure-Python implementation of ElementTree   Part of the standard library since 2 5  cElementTree  Optimized C implementation of ElementTree  Also offered in the standard library since 2 5  LXML  Based on libxml2  Offers a rich superset of the ElementTree API as well XPath  CSS Selectors  and more    Here s an example of how to generate your example document using the in-stdlib cElementTree   import xml etree cElementTree as ET  root   ET Element  root   doc   ET SubElement root   doc    ET SubElement doc   field1   name  blah   text    some value1  ET SubElement doc   field2   name  asdfasd   text    some vlaue2   tree   ET ElementTree root  tree write  filename xml     I ve tested it and it works  but I m assuming whitespace isn t significant  If you need  prettyprint  indentation  let me know and I ll look up how to do that   It may be an LXML-specific option  I don t use the stdlib implementation much   For further reading  here are some useful links    API docs for the implementation in the Python standard library Introductory Tutorial  From the original author s site  LXML etree tutorial   With example code for loading the best available option from all major ElementTree implementations    As a final note  either cElementTree or LXML should be fast enough for all your needs  both are optimized C code   but in the event you re in a situation where you need to squeeze out every last bit of performance  the benchmarks on the LXML site indicate that    LXML clearly wins for serializing  generating  XML As a side-effect of implementing proper parent traversal  LXML is a bit slower than cElementTree for parsing

User · Answer

For such a simple XML structure  you may not want to involve a full blown XML module  Consider a string template for the simplest structures  or Jinja for something a little more complex  Jinja can handle looping over a list of data to produce the inner xml of your document list  That is a bit trickier with raw python string templates  For a Jinja example  see my answer to a similar question   Here is an example of generating your xml with string templates   import string from xml sax saxutils import escape  inner template   string Template       lt field  id  name    name   gt   value  lt  field  id  gt     outer template   string Template     lt root gt    lt doc gt    document list    lt  doc gt   lt  root gt         data          1   foo    The value for the foo document         2   bar    The  lt value gt  for the  lt bar gt  document       inner contents    inner template substitute id id  name name  value escape value   for  id  name  value  in data  result   outer template substitute document list   n  join inner contents   print result   Output     lt root gt    lt doc gt       lt field1 name  foo  gt The value for the foo document lt  field1 gt       lt field2 name  bar  gt The  amp lt value amp gt  for the  amp lt bar amp gt  document lt  field2 gt    lt  doc gt   lt  root gt    The downer of the template approach is that you won t get escaping of  lt  and  gt  for free  I danced around that problem by pulling in a util from xml sax

User · Answer

Yattag http   www yattag org  or https   github com leforestier yattag provides an interesting API to create such XML document  and also HTML documents    It s using context manager and with keyword   from yattag import Doc  indent  doc  tag  text   Doc   tagtext    with tag  root        with tag  doc            with tag  field1   name  blah                text  some value1           with tag  field2   name  asdfasd                text  some value2    result   indent      doc getvalue        indentation       4      newline     r n     print result    so you will get    lt root gt       lt doc gt           lt field1 name  blah  gt some value1 lt  field1 gt           lt field2 name  asdfasd  gt some value2 lt  field2 gt       lt  doc gt   lt  root gt

User · Answer

For the simplest choice  I d go with minidom   http   docs python org library xml dom minidom html    It is built in to the python standard library and is straightforward to use in simple cases   Here s a pretty easy to follow tutorial  http   www boddie org uk python XML intro html

User · Answer

I just finished writing an xml generator  using bigh 29 s method of Templates     it s a nice way of controlling what you output without too many Objects getting  in the way    As for the tag and value  I used two arrays  one which gave the tag name and position in the output xml and another which referenced a parameter file having the same list of tags   The parameter file  however  also has the position number in the corresponding input  csv  file where the data will be taken from  This way  if there s any changes to the position of the data coming in from the input file  the program doesn t change  it dynamically works out the data field position from the appropriate tag in the parameter file

[python] Creating a simple XML file using python

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