Not to discourage anyone from playing with python, but if the aim is to have one command that can query multiple payload xml files at once, asking for just one piece of information at a time (e.g. "What's Joe Blow's shoe size?", "What's Joan of Arc's favourite sport?"), it may be easier to stick with a VC-only solution such as:
<?xml version="1.0" encoding="utf-16"?>
<!--VoxCommando 2.0.0.8-->
<command id="331" name="Get profile info" enabled="true" alwaysOn="False" confirm="False" requiredConfidence="0" loop="False" loopDelay="0" loopMax="0" description="">
<action>
<cmdType>PayloadXML.GetValue</cmdType>
<params>
<param>{2}</param>
<param>{1}</param>
</params>
<cmdRepeat>1</cmdRepeat>
</action>
<if ifBlockDisabled="False" ifNot="True">
<ifType>LastActionSuccess</ifType>
<ifParams>&&</ifParams>
<then>
<action>
<cmdType>OSD.ShowText</cmdType>
<params>
<param>I'm sorry, that information is not available.</param>
</params>
<cmdRepeat>1</cmdRepeat>
</action>
<action>
<cmdType>TTS.Speak</cmdType>
<params>
<param>I'm sorry, that information is not available.</param>
</params>
<cmdRepeat>1</cmdRepeat>
</action>
</then>
<else>
<action>
<cmdType>OSD.ShowText</cmdType>
<params>
<param>The information I have says: {LastResult}</param>
</params>
<cmdRepeat>1</cmdRepeat>
</action>
<action>
<cmdType>TTS.Speak</cmdType>
<params>
<param>The info I have says: {LastResult}.|According to your records, {LastResult}.</param>
</params>
<cmdRepeat>1</cmdRepeat>
</action>
</else>
</if>
<phrase>What, Who</phrase>
<phrase>is, are</phrase>
<payloadFromXML phraseOnly="True" use2partPhrase="False" phraseConnector="by" Phrase2wildcard="anyone" optional="False">payloads\contacts.xml</payloadFromXML>
<payloadFromXML phraseOnly="False" use2partPhrase="False" phraseConnector="by" Phrase2wildcard="anyone" optional="False">payloads\xml_filepaths.xml</payloadFromXML>
</command>
The above requires 2 payload xml files -- one with your contact names, the other one has the file paths for each payload xml file of interest. I've attached an example of the latter, which I hope will clarify what I mean.
This is akin to the method you described wanting to use in python.