xml search and update using python - python-3.x

Question

my sample xml object is:
<Assessment version="10" dateCreated="4/19/2020 10:41:20 PM">
<Section name="Space">
<Glossary>
<Item name="***"><b>Indicates high priority data that is required</b></Item>
</Glossary>
<InputNumber type="int" min="0" max="100" title="[1a] q2 some data">
<Value>20</Value>
</InputNumber>
<InputNumber type="int" min="0" max="10000" title="[2] some data">
<Value>1</Value>
</InputNumber>
<InputNumber type="int" min="0" max="10000" title="[3] some text">
<Value>2</Value>
</InputNumber>
</Section>
<Section name="Power">
<Glossary>
<Item name="***"><b>Indicates high priority data that is required</b></Item>
</Glossary>
<InputNumber type="int" min="0" max="100000" title="[8] some text">
<Value>15</Value>
</InputNumber>
<PickList title="[11] some text">
<Option selected="true">Yes</Option>
<Option>No</Option>
<Option>there is no UPS</Option>
</PickList>
</Section>
<Section name="Cooling">
<Glossary>
<Item name="***"><b>Indicates high priority data that is required</b></Item>
</Glossary>
<InputNumber type="int" min="0" max="100000" title="[18] some text">
<Value>30</Value>
</InputNumber>
</InputText>
<InputText title="[21] some data">
<Value>3</Value>
</InputText>
</Section>
<Section name="Comments">
<InputTextArea title="[22] General Comments" format="normal">
<Value>test value for capacity assessment test by monika</Value>
</InputTextArea>
</Section>
</Assessment>
i get this from database
In my python script:
template= cursor.fetchall()
for row in template:
#xmlTemplate = ET.ElementTree(ET.fromstring(row[6]))
xmlTemplateStr = row[6]
xmlTemplate = ET.ElementTree(ET.fromstring(xmlTemplateStr))
root = ET.fromstring(xmlTemplateStr)
i need to find the node based on the number and update the value of that perticular node
for example:
if in need to update the following value to 4:
</InputText>
<InputText title="[21] some data">
<Value>3</Value>
</InputText>
i need to search the node with key as [21] and update the value of that node to 4
</InputText>
<InputText title="[21] some data">
<Value>4</Value>
</InputText>
How do i do it?

Answer 1

You can do this with lxml, using xpath:
assess = """[your xml above - corrected]""" #note: the sample xml in the question was invalid because it had an extra tag
from lxml import etree
doc = etree.XML(assess.encode('utf-8'))
val = doc.xpath('//InputText[#title="[21] some data"]/Value')
val[0].text = '4'
print(etree.tostring(doc).decode())
Relevant part of the output:
<InputText title="[21] some data">
<Value>4</Value>
</InputText>