parsing xml in python

Question

I want to parse text from a xml file.Consider that I have a some lines in a file.xml

<s id="1792387-2">Castro Verde is situated in the Baixo Alentejo Subregion within a territory known locally as the Campo Branco (English: White Plains).</s>

How can I extract the following text from the above line:

Castro Verde is situated in the Baixo Alentejo Subregion within a territory known locally as the Campo Branco (English: White Plains).

And after making some changes with the text, I want to get return the change text with the same tag as like below.

<s id="1792387-2"> Changed Text </s>

Any suggestion please.Thanks!

What exactly is your question? – Daniel Roseman Aug 01 '11 at 15:20 — Daniel Roseman, Aug 01 '11 at 15:20
Do you want to parse the text, the XML or both? – Legolas Aug 01 '11 at 15:22 — Legolas, Aug 01 '11 at 15:22

score 5 · Accepted Answer · answered Aug 01 '11 at 15:26

5

LXML makes this particularly easy.

>>> from lxml import etree
>>> text = '''<s id="1792387-2">Castro Verde is situated in the Baixo Alentejo Subregion within a territory known locally as the Campo Branco (English: White Plains).</s>'''
>>> def edit(s):
...     return 'Changed Text'
... 
>>> t = etree.fromstring(text)
>>> t.text = edit(t.text)
>>> etree.tostring(t)
'<s id="1792387-2">Changed Text</s>'

answered Aug 01 '11 at 15:26

Fred Foo

355,277
75
744
836

getting Traceback `Traceback (most recent call last): File "", line 1, in builtins.ImportError: No module named lxml` – Blue Ice Aug 01 '11 at 15:29
1

@Blue Ice: LXML is not a Python built-in module, you have to install it separately. http://lxml.de – Fred Foo Aug 01 '11 at 15:30
If you'd like to just use the standard library (python 2.5+) you can use the ElementTree module (see my answer). – David Wolever Aug 01 '11 at 15:34
But, I am working in server & for the momentum not possible to do it , since no administration access.Any other alternatives please! – Blue Ice Aug 01 '11 at 15:35

David Wolever · Answer 2 · 2011-08-01T15:38:29.333

4

There are a couple stdlib methods for parsing xml… But in general ElementTree is the simplest:

from xml.etree import ElementTree
from StringIO import StringIO
doc = ElementTree.parse(StringIO("""<doc><s id="1792387-2">Castro…</s><s id="1792387-3">Other stuff</s></doc>"""))
for elem in doc.findall("s"):
    print "Text:", elem.text
    elem.text = "new text"
    print "New:", ElementTree.dump(elem)

And if your XML is coming from a file, you can use:

f = open("path/to/foo.xml")
doc = ElementTree.parse(f)
f.close()
… use `doc` …

edited Aug 01 '11 at 15:38

answered Aug 01 '11 at 15:33

David Wolever

148,955
89
346
502

Could you please have a look the following Traceback `Traceback (most recent call last): File "", line 1, in builtins.ImportError: No module named StringIO` – Blue Ice Aug 01 '11 at 15:38
What version of Python are you using? (`python --version`) – David Wolever Aug 01 '11 at 15:39
Hrm… Is it a custom or restricted installation? Because StringIO should exist. Anyway, you can try loading it from a file (as per the second portion of my answer). – David Wolever Aug 01 '11 at 15:47
Just to be sure: is it possible you have multiple versions of Python installed? In Python 3 it is changed to `from StringIO import StringIO`. I have two Pythons on my system (2.6 and 3.2) and get into such a situation from time to time. – Legolas Aug 01 '11 at 15:54

Legolas · Answer 3 · 2011-08-01T15:44:38.243

1

Parsing XML using the dom package (part of Python) http://docs.python.org/py3k/library/xml.dom.minidom.html is my favorite:

import xml.dom.minidom
d = xml.dom.minidom.parseString("<s id=\"1792387-2\">Castro Verde is situated in the Baixo Alentejo Subregion within a territory known locally as the Campo Branco (English: White Plains).</s>")
oldText = d.childNodes[0].childNodes[0].data
d.childNodes[0].childNodes[0].data = "Changed text"
d.toxml()

But this does not help you parse the text, so I am not sure what you exactly want there.

edited Aug 01 '11 at 15:44

answered Aug 01 '11 at 15:32

Legolas

1,432
10
11

I want to extract the following text from the above line: `Castro Verde is situated in the Baixo Alentejo Subregion within a territory known locally as the Campo Branco (English: White Plains).` – Blue Ice Aug 01 '11 at 15:42

parsing xml in python

3 Answers3