Python: How to get value from specific element from xml file

Question

I'm using xml.etree.ElementTree

My XML looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<Document xmlns="urn:iso:std:iso:20022:tech:xsd:pain.0668.011.02" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:iso:std:iso:20022:tech:xsd:pain.008.001.02 pain.0668.011.02.xsd"> 
    <CstmrDrctDbtInitn>
        <GrpHdr>
            <MsgId>cca82067341ea996fc89c17afb5</MsgId>
            <CreDtTm>2021-07-10T23:03:11Z</CreDtTm>
            <NbOfTxs>64</NbOfTxs>
            <CtrlSum>1334.82</CtrlSum>
            <InitgPty>
                <Nm>Example Company</Nm>
            </InitgPty>
        </GrpHdr>
        <PmtInf>
            <PmtInfId>cca82067341ea996fc89c17afb5</PmtInfId>
            <PmtMtd>EN</PmtMtd>
            <NbOfTxs>64</NbOfTxs>
            <CtrlSum>1334.82</CtrlSum>
            <PmtTpInf>
                <SvcLvl>
                    <Cd>NORM</Cd>
                </SvcLvl>
                <LclInstrm>
                    <Cd>MAIN</Cd>
                </LclInstrm>
                <SeqTp>RCUR</SeqTp>
            </PmtTpInf>
        </PmtInf>
    </CstmrDrctDbtInitn> 
</Document> 

I want to get all values from Element CtrlSum and write them into a dataframe.

My problem is the <Document xmlns...> Tag, which currently prevents me from accessing other values.

I have tried to access the all elements with

tree = et.parse('xml_beispiel.xml')
root = tree.getroot()
root.findall(".") 

or

root.findall(".//GrpHdr")

but only get empty values or the values from <Document xmlns...>

Answer 1

You have to deal with your namespaces; try this:

ns = {'': 'urn:iso:std:iso:20022:tech:xsd:pain.0668.011.02'}
root.find('.//GrpHdr/CtrlSum',namespaces=ns).text

and see if it works.