Empty lines while using minidom.toprettyxml

I've been using a minidom.toprettyxml for prettify my xml file. When I'm creating XML file and using this method, all works grate, but if I use it after I've modified the xml file (for examp I've added an additional nodes) and then I'm writing it back to XML, I'm getting empty lines, each time I'm updating it, I'm getting more and more empty lines...

my code :

file.write(prettify(xmlRoot))


def prettify(elem):
    rough_string = xml.tostring(elem, 'utf-8') //xml as ElementTree
    reparsed = mini.parseString(rough_string) //mini as minidom
    return reparsed.toprettyxml(indent=" ")

and the result :

<?xml version="1.0" ?>
<testsuite errors="0" failures="3" name="TestSet_2013-01-23 14_28_00.510935" skip="0"     tests="3" time="142.695" timestamp="2013-01-23 14:28:00.515460">




    <testcase classname="TC test" name="t1" status="Failed" time="27.013"/>




    <testcase classname="TC test" name="t2" status="Failed" time="78.325"/>


    <testcase classname="TC test" name="t3" status="Failed" time="37.357"/>
</testsuite>

any suggestions ?

thanks.

Solution

I found a solution here: http://code.activestate.com/recipes/576750-pretty-print-xml/

Then I modified it to take a string instead of a file.

from xml.dom.minidom import parseString

pretty_print = lambda data: '\n'.join([line for line in parseString(data).toprettyxml(indent=' '*2).split('\n') if line.strip()])

Output:

<?xml version="1.0" ?>
<testsuite errors="0" failures="3" name="TestSet_2013-01-23 14_28_00.510935" skip="0" tests="3" time="142.695" timestamp="2013-01-23 14:28:00.515460">
  <testcase classname="TC test" name="t1" status="Failed" time="27.013"/>
  <testcase classname="TC test" name="t2" status="Failed" time="78.325"/>
  <testcase classname="TC test" name="t3" status="Failed" time="37.357"/>
</testsuite>

This may help you work it into your function a little be easier:

def new_prettify():
    reparsed = parseString(CONTENT)
    print '\n'.join([line for line in reparsed.toprettyxml(indent=' '*2).split('\n') if line.strip()])