Extracting a value from an xml file

[ironmonkey69]

Is there a way to use python to extract a value from an xml file?

[KaezarRex]

Is there a way to use python to extract a value from an xml file?

There are many different ways to parse xml in python. I would suggest looking into a module called minidom in the python library reference. They have a simple example to help you get started.

[ironmonkey69]

I can use the code below to parse the file, but how can I extract a value of a tag such as 'name' with a value and return that value to an external program?

from xml.dom.minidom import parse, parseString
dom1 = parse('c:\\temp\\mydata.xml') # parse an XML file by name

[ironmonkey69]

this is what the contents of the xml file looks like and I want to take the value of 'name' and return that to an external program.

<servicing name="color-measure-print-and-scan">

[KaezarRex]

this is what the contents of the xml file looks like and I want to take the value of 'name' and return that to an external program.

<servicing name="color-measure-print-and-scan">

[CODE=python]elements = dom1.getElement sByTagName("ser vicing")
return elements[0].attributes['name'].value[/CODE]
If you have multiple servicing tags, just iterate through elements instead of only looking at the first index.

[ironmonkey69]

My python script looks like this

import xml.dom.minidom

from xml.dom.minidom import parse, parseString
dom1 = parse('/home/test.xml') # parse an XML file by name
elements = dom1.getElementsByTagName("servicing")
	return elements[0].attributes['name'].value

I get an error that says that return is outside function. I am using python 2.0.

[KaezarRex]

My python script looks like this

import xml.dom.minidom

from xml.dom.minidom import parse, parseString
dom1 = parse('/home/test.xml') # parse an XML file by name
elements = dom1.getElementsByTagName("servicing")
	return elements[0].attributes['name'].value

I get an error that says that return is outside function. I am using python 2.0.

Sorry, I misunderstood what you mean by returning the value to an external program.
Try this:
[CODE=python]import xml.dom.minidom
from xml.dom.minidom import parse, parseString
dom1 = parse('/home/test.xml')
elements = dom1.getElement sByTagName("ser vicing")
name = elements[0].attributes['name'].value
print name[/CODE]

[ironmonkey69]

when i run this script, it says "ImportErro r: No module named xml.dom.minidom "
Is there any other way to perform this function without using minidom?

[KaezarRex]

when i run this script, it says "ImportErro r: No module named xml.dom.minidom "
Is there any other way to perform this function without using minidom?

That's strange that it won't import because minidom is automatically included in python. I am using 2.5, but I'm almost positive that the minidom module should work the same as in 2.0.
As far as other ways to parse go, I have only used minidom to extract info from xml files, so I don't know of any other way to recommend.

[bartonc]

That's strange that it won't import because minidom is automatically included in python. I am using 2.5, but I'm almost positive that the minidom module should work the same as in 2.0.
As far as other ways to parse go, I have only used minidom to extract info from xml files, so I don't know of any other way to recommend.

Yep. And 2.4.4 the docs chapter is "13.7 xml.dom.minidom ".

[bartonc]

when i run this script, it says "ImportErro r: No module named xml.dom.minidom "
Is there any other way to perform this function without using minidom?

This also makes no sense to me because you made it past the import in your reply #6. Something has changed since then. Can you think what that might be?

[ironmonkey69]

Is there a way to parse the xml file using the xmllib?

[ghostdog74]

this is what the contents of the xml file looks like and I want to take the value of 'name' and return that to an external program.

<servicing name="color-measure-print-and-scan">

its only 1 line? can you show more sample of your xml file, if any?

[ironmonkey69]

sure

[CODE=xml]
<servicing name="alignment ">

<!-- *************** *************** ****** BEGIN OF PASS *************** *************** ************ -->

<!-- TRJ-002448 Changed to prevent the carriage from going to the secondary spittoon during printhead alignment
plots. This happens because the printmode is a mix of uni-directional and bi-directional print modes. Date 11th April 2006 -->
<begin-of-pass>
<flying-spit type="fixed">
<parameters>
<fixed mode="only-SVS"/>
</parameters>
</flying-spit>
</begin-of-pass>


<!-- *************** *************** ****** BEGIN OF PAGE *************** *************** ************ -->

<!-- Disable drop detection -->
<begin-of-page>
<drop-detection enabled="0">
</drop-detection>
</begin-of-page>


<!-- *************** *************** ****** END OF JOB *************** *************** ************ -->

<!-- Disable drop detection -->
<end-of-job>
<drop-detection enabled="0">
</drop-detection>
</end-of-job>

</servicing>
[/CODE]

[bvdet]

sure

[CODE=xml]
<servicing name="alignment ">

<!-- *************** *************** ****** BEGIN OF PASS *************** *************** ************ -->

<!-- TRJ-002448 Changed to prevent the carriage from going to the secondary spittoon during printhead alignment
plots. This happens because the printmode is a mix of uni-directional and bi-directional print modes. Date 11th April 2006 -->
<begin-of-pass>
<flying-spit type="fixed">
<parameters>
<fixed mode="only-SVS"/>
</parameters>
</flying-spit>
</begin-of-pass>


<!-- *************** *************** ****** BEGIN OF PAGE *************** *************** ************ -->

<!-- Disable drop detection -->
<begin-of-page>
<drop-detection enabled="0">
</drop-detection>
</begin-of-page>


<!-- *************** *************** ****** END OF JOB *************** *************** ************ -->

<!-- Disable drop detection -->
<end-of-job>
<drop-detection enabled="0">
</drop-detection>
</end-of-job>

</servicing>
[/CODE]

If all you want to do is read that one value, you might consider a regex solution:[code=Python]import re

keyword = 'servicing'
patt = re.compile(r'<% s(.*)>' % keyword)

s = patt.search(ope n('file_name.xm l').read()).gro up(1)
if '=' in s:
print s.split('=')[1][/code]

Output:
>>> "alignment"