Python pretty print an XML given an XML string

Here's how to parse from a text string to the lxml structured data type.

Python 2:

from lxml import etreexml_str = "<parent><child>text</child><child>other text</child></parent>"root = etree.fromstring(xml_str)print etree.tostring(root, pretty_print=True)

Python 3:

from lxml import etreexml_str = "<parent><child>text</child><child>other text</child></parent>"root = etree.fromstring(xml_str)print(etree.tostring(root, pretty_print=True).decode())

Outputs:

<parent>  <child>text</child>  <child>other text</child></parent>

I use the lxml library, and there it's as simple as

>>> print(etree.tostring(root, pretty_print=True))

You can do that operation using any etree, which you can either generate programmatically, or read from a file.

If you're using the DOM from PyXML, it's

import xml.dom.extxml.dom.ext.PrettyPrint(doc)

That prints to the standard output, unless you specify an alternate stream.

http://pyxml.sourceforge.net/topics/howto/node19.html

To directly use the minidom, you want to use the toprettyxml() function.

http://docs.python.org/library/xml.dom.minidom.html#xml.dom.minidom.Node.toprettyxml

Here's a Python3 solution that gets rid of the ugly newline issue (tons of whitespace), and it only uses standard libraries unlike most other implementations. You mention that you have an xml string already so I am going to assume you used xml.dom.minidom.parseString()

With the following solution you can avoid writing to a file first:

import xml.dom.minidomimport osdef pretty_print_xml_given_string(input_string, output_xml):    """    Useful for when you are editing xml data on the fly    """    xml_string = input_string.toprettyxml()    xml_string = os.linesep.join([s for s in xml_string.splitlines() if s.strip()]) # remove the weird newline issue    with open(output_xml, "w") as file_out:        file_out.write(xml_string)

I found how to fix the common newline issue here.