How to modify XML element using Python Elementtree

Question

I would like to modify a key value of an attribute(eg Change the value of "strokeColor" inside the "style" attribute), and the other values of this attribute can not be changed. I'm using Python's ElementTree included with Python.

Here is an example of what I did before:

Part of my XML example code:

<?xml version="1.0"?>
<mxCell edge="1" id="line1" parent="1" source="main_wins" style="endArrow=none;html=1;entryX=0;entryY=0.25;entryDx=0;entryDy=0;strokeWidth=5;strokeColor=#32AC2D;rounded=0;edgeStyle=orthogonalEdgeStyle;exitX=1;exitY=0.5;exitDx=0;exitDy=0;" target="main-switch" value="">
</mxCell>

My python code:

import xml.etree.ElementTree as ET
tree = ET.parse('example.xml')
target = tree.find('.//mxCell[@id="line1"]')
target.set("strokeColor","#FF0000")
tree.write('output.xml')

My output XML:

<?xml version="1.0"?>
<mxCell edge="1" id="line1" parent="1" source="main_wins" strokeColor="#FF0000" style="endArrow=none;html=1;entryX=0;entryY=0.25;entryDx=0;entryDy=0;strokeWidth=5;strokeColor=#32AC2D;rounded=0;edgeStyle=orthogonalEdgeStyle;exitX=1;exitY=0.5;exitDx=0;exitDy=0;" target="main-switch" value="">
</mxCell>

As you can see, there is a new attribute called "strokeColor", but not changing the strokeColor value inside the "style" attribute. I want to change the strokeColor inside "style" attribute. How can I fix this?

Answer 1

Another method.

from simplified_scrapy import SimplifiedDoc, utils, req
html = '''
<?xml version="1.0"?>
<mxCell edge="1" id="line1" parent="1" source="main_wins" style="endArrow=none;html=1;entryX=0;entryY=0.25;entryDx=0;entryDy=0;strokeWidth=5;strokeColor=#32AC2D;rounded=0;edgeStyle=orthogonalEdgeStyle;exitX=1;exitY=0.5;exitDx=0;exitDy=0;" target="main-switch" value="">
</mxCell>
'''

doc = SimplifiedDoc(html)
mxCell = doc.select('mxCell#line1')
style = doc.replaceReg(mxCell['style'],'strokeColor=.*?;','strokeColor=#FF0000;')
mxCell.setAttr('style',style)
print(doc.html)

Result:

<?xml version="1.0"?>
<mxCell edge="1" id="line1" parent="1" source="main_wins" style="endArrow=none;html=1;entryX=0;entryY=0.25;entryDx=0;entryDy=0;strokeWidth=5;strokeColor=#FF0000;rounded=0;edgeStyle=orthogonalEdgeStyle;exitX=1;exitY=0.5;exitDx=0;exitDy=0;" target="main-switch" value="">
</mxCell>

Here are more examples: https://github.com/yiyedata/simplified-scrapy-demo/tree/master/doc_examples