What is the best way (or are the various ways) to pretty print XML in Python?
27 Answers
import xml.dom.minidom
dom = xml.dom.minidom.parse(xml_fname) # or xml.dom.minidom.parseString(xml_string)
pretty_xml_as_string = dom.toprettyxml()
lxml is recent, updated, and includes a pretty print function
import lxml.etree as etree
x = etree.parse("filename")
print etree.tostring(x, pretty_print=True)
Check out the lxml tutorial: http://lxml.de/tutorial.html
Another solution is to borrow this indent function, for use with the ElementTree library that's built in to Python since 2.5.
Here's what that would look like:
from xml.etree import ElementTree
def indent(elem, level=0):
i = "\n" + level*" "
j = "\n" + (level-1)*" "
if len(elem):
if not elem.text or not elem.text.strip():
elem.text = i + " "
if not elem.tail or not elem.tail.strip():
elem.tail = i
for subelem in elem:
indent(subelem, level+1)
if not elem.tail or not elem.tail.strip():
elem.tail = j
else:
if level and (not elem.tail or not elem.tail.strip()):
elem.tail = j
return elem
root = ElementTree.parse('/tmp/xmlfile').getroot()
indent(root)
ElementTree.dump(root)
As of Python 3.9, ElementTree has an indent() function for pretty-printing XML trees.
See https://docs.python.org/3/library/xml.etree.elementtree.html#xml.etree.ElementTree.indent.
Sample usage:
import xml.etree.ElementTree as ET
element = ET.XML("<html><body>text</body></html>")
ET.indent(element)
print(ET.tostring(element, encoding='unicode'))
The upside is that it does not require any additional libraries. For more information check https://bugs.python.org/issue14465 and https://github.com/python/cpython/pull/15200
If you have xmllint you can spawn a subprocess and use it. xmllint --format <file> pretty-prints its input XML to standard output.
Note that this method uses an program external to python, which makes it sort of a hack.
def pretty_print_xml(xml):
proc = subprocess.Popen(
['xmllint', '--format', '/dev/stdin'],
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
)
(output, error_output) = proc.communicate(xml);
return output
print(pretty_print_xml(data))
If you're using a DOM implementation, each has their own form of pretty-printing built-in:
# minidom
#
document.toprettyxml()
# 4DOM
#
xml.dom.ext.PrettyPrint(document, stream)
# pxdom (or other DOM Level 3 LS-compliant imp)
#
serializer.domConfig.setParameter('format-pretty-print', True)
serializer.writeToString(document)
If you're using something else without its own pretty-printer — or those pretty-printers don't quite do it the way you want — you'd probably have to write or subclass your own serialiser.
I had some problems with minidom's pretty print. I'd get a UnicodeError whenever I tried pretty-printing a document with characters outside the given encoding, eg if I had a β in a document and I tried doc.toprettyxml(encoding='latin-1'). Here's my workaround for it:
def toprettyxml(doc, encoding):
"""Return a pretty-printed XML document in a given encoding."""
unistr = doc.toprettyxml().replace(u'<?xml version="1.0" ?>',
u'<?xml version="1.0" encoding="%s"?>' % encoding)
return unistr.encode(encoding, 'xmlcharrefreplace')
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.
import xml.etree.ElementTree as ET
import xml.dom.minidom
import os
def pretty_print_xml_given_root(root, output_xml):
"""
Useful for when you are editing xml data on the fly
"""
xml_string = xml.dom.minidom.parseString(ET.tostring(root)).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)
def pretty_print_xml_given_file(input_xml, output_xml):
"""
Useful for when you want to reformat an already existing xml file
"""
tree = ET.parse(input_xml)
root = tree.getroot()
pretty_print_xml_given_root(root, output_xml)
I found how to fix the common newline issue here.
XML pretty print for python looks pretty good for this task. (Appropriately named, too.)
An alternative is to use pyXML, which has a PrettyPrint function.
You can try this variation...
Install BeautifulSoup and the backend lxml (parser) libraries:
user$ pip3 install lxml bs4
Process your XML document:
from bs4 import BeautifulSoup
with open('/path/to/file.xml', 'r') as doc:
for line in doc:
print(BeautifulSoup(line, 'lxml-xml').prettify())
For converting an entire xml document to a pretty xml document
(ex: assuming you've extracted [unzipped] a LibreOffice Writer .odt or .ods file, and you want to convert the ugly "content.xml" file to a pretty one for automated git version control and git difftooling of .odt/.ods files, such as I'm implementing here)
import xml.dom.minidom
file = open("./content.xml", 'r')
xml_string = file.read()
file.close()
parsed_xml = xml.dom.minidom.parseString(xml_string)
pretty_xml_as_string = parsed_xml.toprettyxml()
file = open("./content_new.xml", 'w')
file.write(pretty_xml_as_string)
file.close()
References:
- Thanks to Ben Noland's answer on this page which got me most of the way there.
from lxml import etree
import xml.dom.minidom as mmd
xml_root = etree.parse(xml_fiel_path, etree.XMLParser())
def print_xml(xml_root):
plain_xml = etree.tostring(xml_root).decode('utf-8')
urgly_xml = ''.join(plain_xml .split())
good_xml = mmd.parseString(urgly_xml)
print(good_xml.toprettyxml(indent=' ',))
It's working well for the xml with Chinese!
If for some reason you can't get your hands on any of the Python modules that other users mentioned, I suggest the following solution for Python 2.7:
import subprocess
def makePretty(filepath):
cmd = "xmllint --format " + filepath
prettyXML = subprocess.check_output(cmd, shell = True)
with open(filepath, "w") as outfile:
outfile.write(prettyXML)
As far as I know, this solution will work on Unix-based systems that have the xmllint package installed.
I found this question while looking for "how to pretty print html"
Using some of the ideas in this thread I adapted the XML solutions to work for XML or HTML:
from xml.dom.minidom import parseString as string_to_dom
def prettify(string, html=True):
dom = string_to_dom(string)
ugly = dom.toprettyxml(indent=" ")
split = list(filter(lambda x: len(x.strip()), ugly.split('\n')))
if html:
split = split[1:]
pretty = '\n'.join(split)
return pretty
def pretty_print(html):
print(prettify(html))
When used this is what it looks like:
html = """\
<div class="foo" id="bar"><p>'IDK!'</p><br/><div class='baz'><div>
<span>Hi</span></div></div><p id='blarg'>Try for 2</p>
<div class='baz'>Oh No!</div></div>
"""
pretty_print(html)
Which returns:
<div class="foo" id="bar">
<p>'IDK!'</p>
<br/>
<div class="baz">
<div>
<span>Hi</span>
</div>
</div>
<p id="blarg">Try for 2</p>
<div class="baz">Oh No!</div>
</div>
Use etree.indent and etree.tostring
import lxml.etree as etree
root = etree.fromstring('<html><head></head><body><h1>Welcome</h1></body></html>')
etree.indent(root, space=" ")
xml_string = etree.tostring(root, pretty_print=True).decode()
print(xml_string)
output
<html>
<head/>
<body>
<h1>Welcome</h1>
</body>
</html>
Removing namespaces and prefixes
import lxml.etree as etree
def dump_xml(element):
for item in element.getiterator():
item.tag = etree.QName(item).localname
etree.cleanup_namespaces(element)
etree.indent(element, space=" ")
result = etree.tostring(element, pretty_print=True).decode()
return result
root = etree.fromstring('<cs:document xmlns:cs="http://blabla.com"><name>hello world</name></cs:document>')
xml_string = dump_xml(root)
print(xml_string)
output
<document>
<name>hello world</name>
</document>
I found a fast and easy way to nicely format and print an xml file:
import xml.etree.ElementTree as ET
xmlTree = ET.parse('your XML file')
xmlRoot = xmlTree.getroot()
xmlDoc = ET.tostring(xmlRoot, encoding="unicode")
print(xmlDoc)
Outuput:
<root>
<child>
<subchild>.....</subchild>
</child>
<child>
<subchild>.....</subchild>
</child>
...
...
...
<child>
<subchild>.....</subchild>
</child>
</root>
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