Pyhton XML SAX help

[leegold2]

Hi,

I'm new at this- trying Python SAX parser. I'm obviously doing something wrong. Below please find the error message, code and the xml. Be grateful to learn what I'm doing wrong - it's probably a basic concept...

error message:

Traceback (most recent call last):
File "C:\Python24\Lib\site-packages\pythonwin\pywin\framework\scriptutils.py", line 310, in RunScript
exec codeObject in __main__.__dict__
File "C:\pythonscripts\xml\parse3.py", line 37, in ?
parser.parse(r'C:\perlscripts\xml\Document2.kml')
File "C:\Python24\lib\xml\sax\expatreader.py", line 107, in parse
xmlreader.IncrementalParser.parse(self, source)
File "C:\Python24\lib\xml\sax\xmlreader.py", line 123, in parse
self.feed(buffer)
File "C:\Python24\lib\xml\sax\expatreader.py", line 207, in feed
self._parser.Parse(data, isFinal)
File "C:\Python24\lib\xml\sax\expatreader.py", line 303, in end_element
self._cont_handler.endElement(name)
File "C:\pythonscripts\xml\parse3.py", line 31, in endElement
print self.description, str(self.coordinates)
AttributeError: G_Handler instance has no attribute 'description'
>>>

Code:

from xml.sax import make_parser
from xml.sax.handler import ContentHandler
import string

class G_Handler(ContentHandler):

def __init__ (self):
self.isdescriptionElement = 0
self.iscoordinatesElement = 0

def startElement(self, name , attrs):
if name == 'description':
self.isdescriptionElement= 1
self.description = ""
if name == 'coordinates':
self.iscoordinatesElement = 1
self.coordinates = ""


def characters (self, ch):
if self.isdescriptionElement == 1:
self.description = ch
if self.iscoordinatesElement == 1:
self.coordinates = ch

def endElement(self, name):
if name == 'description':
self.isdescriptionElement= 0
if name == 'coordinates':
self.iscoordinatesElement = 0
print self.description, str(self.coordinates)

parser = make_parser()
parser.setContentHandler(G_Handler())
parser.parse(r'C:\perlscripts\xml\Document2.kml')


XML:

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="

http://earth.google.com/kml/2.1">

<Document>

<name>Paths</name>
<description>Path from Atlanta to Nashville</description>
<Style id="yellowLineGreenPoly">
<LineStyle>
<color>7f00ffff</color>
<width>4</width>
</LineStyle>
<PolyStyle>
<color>7f00ff00</color>
</PolyStyle>
</Style>

<Placemark>
<name>Atlanta to Nashville</name>
<description>
abc
</description>
<styleUrl>#yellowLineGreenPoly</styleUrl>
<Point>
<extrude>1</extrude>
<tessellate>1</tessellate>
<altitudeMode>absolute</altitudeMode>
<coordinates>
84.4,33.7
</coordinates>
</Point>
</Placemark>



<Placemark>
<name>Atlanta to Nashville</name>
<description>
abc
</description>
<styleUrl>#yellowLineGreenPoly</styleUrl>
<Point>
<extrude>1</extrude>
<tessellate>1</tessellate>
<altitudeMode>absolute</altitudeMode>
<coordinates>
-86.7,36.1
</coordinates>
</Point>
</Placemark>

</Document>
</kml>

 

[mikrom]

Python says AttributeError: G_Handler instance has no attribute 'description' and exactly that he means

You create the attribute self.description = "" with the method startElement() only if the name == 'description'.
That is, if the name != 'description' the instance of the class G_handler does not have such an attribute.
And if you look inside in your xml-file, you will see, that there are much more tags - not only 'description' and 'coordinates'

So you need to change the method endElement() to this

    def endElement(self, name):
        if name == 'description':
            self.isdescriptionElement= 0
            print  self.description
        if name == 'coordinates':
            self.iscoordinatesElement = 0
            print  str(self.coordinates)

Now the Error Mesage is gone.