How to get data inside a Tag line in arXml using python?

Question

<?xml version="1.0" encoding="UTF-8"?>
<!-- Generated by ABREX Ver. 1.1.0 -->
<AUTOSAR xmlns="http://autosar.org/schema/r4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://autosar.org/schema/r4.0 AUTOSAR_4-0-3_STRICT.xsd">
    <AR-PACKAGES>
        <AR-PACKAGE>
            <SHORT-NAME>Ecuc</SHORT-NAME>
            <ELEMENTS>
                <ECUC-MODULE-CONFIGURATION-VALUES>
                    <SHORT-NAME>Os</SHORT-NAME>
                    <DEFINITION-REF DEST="ECUC-MODULE-DEF">/AUTOSAR/EcucDefs/Os</DEFINITION-REF>
                    <ECUC-DEF-EDITION>4.2.0</ECUC-DEF-EDITION>
                    <IMPLEMENTATION-CONFIG-VARIANT>VARIANT-PRE-COMPILE</IMPLEMENTATION-CONFIG-VARIANT>
                    <CONTAINERS>
                        <ECUC-CONTAINER-VALUE>
                            <SHORT-NAME>OsInclude</SHORT-NAME>
                            <DEFINITION-REF DEST="ECUC-PARAM-CONF-CONTAINER-DEF">/AUTOSAR/EcucDefs/Os/OsInclude</DEFINITION-REF>
                            <PARAMETER-VALUES>
                                <ECUC-TEXTUAL-PARAM-VALUE>
                                    <DEFINITION-REF DEST="ECUC-STRING-PARAM-DEF">/AUTOSAR/EcucDefs/Os/OsInclude/OsIncludeFileName</DEFINITION-REF>
                                    <VALUE>sample1.h</VALUE>
                                </ECUC-TEXTUAL-PARAM-VALUE>
                            </PARAMETER-VALUES>
                        </ECUC-CONTAINER-VALUE>
                        <ECUC-CONTAINER-VALUE>
                            <SHORT-NAME>AppMode1</SHORT-NAME>
                            <DEFINITION-REF DEST="ECUC-PARAM-CONF-CONTAINER-DEF">/AUTOSAR/EcucDefs/Os/OsAppMode</DEFINITION-REF>
                        </ECUC-CONTAINER-VALUE>                     
                </ECUC-MODULE-CONFIGURATION-VALUES>
            </ELEMENTS>
        </AR-PACKAGE>
    </AR-PACKAGES>
</AUTOSAR>

I tried this code but failed to do it. This is my code. I want to find the value of the Tag from DEFINITION-REF, which is DEST=ECUC-ENUMERATION-PARAM-DEF. But I am not able to get the value of DEST. when I run the below code, I got this error

self._root = parser._parse_whole(source) xml.etree.ElementTree.ParseError: XML or text declaration not at start of entity: line 3, column 0 "

import xml.etree.ElementTree as ET

root = ET.parse('sudh.arxml').getroot()


#run this, and it will list the key value pairs for DEFINITION-REF element : 
for entry in root.findall(".//{http://autosar.org/schema/r4.0}DEFINITION-REF"):
    print(entry.attrib)