Element Tree Xpath

[hey_arnold]

I am trying to extract certain data from the XML using Element tree, but I am unsure why my code doesn't work, any guidance would be helpful.

It appears that the paths I have used aren't correct as no values are returned. I think I am fairly close..... hopefully?

import requests
from lxml import etree
     
fromDate = "2018-07-29"
 
def getXML():
    url="http://energywatch.natgrid.co.uk/EDP-PublicUI/PublicPI/InstantaneousFlowWebService.asmx"
    headers = {'content-type': 'application/soap+xml; charset=utf-8'}
    body ="""<soap12:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap12="http://www.w3.org/2003/05/soap-envelope">
  <soap12:Body>
    <GetInstantaneousFlowData xmlns="http://www.NationalGrid.com/EDP/UI/" />
  </soap12:Body>
</soap12:Envelope>"""
 
    response = requests.post(url,data=body,headers=headers)
    return response.content
 
import pandas as pd
df1 = pd.DataFrame(columns=("applicable_at","name","value","created_date"))   
for pd_date in pd.date_range(fromDate, periods=1):
    day = pd_date.strftime('%Y-%m-%d')
      
    root = etree.fromstring(getXML())
    #map prefix 'd' to the default namespace URI
    ns = {'d': 'http://www.nationalgrid.com/EDP/BusinessEntities/Public'}
      
    publication_objects = root.xpath('//d:EDPObjectCollection', namespaces=ns)
      
    for obj in publication_objects:
        name = obj.find('d:EDPObjectName', ns).text
      
        for data in obj.findall('d:EnergyDataList/d:EDPEnergyDataBE', ns):
            applicable_at = pd.to_datetime(data.find('d:ApplicableAt', ns).text)    
            value = float(data.find('d:FlowRate', ns).text)
            created_date = pd.to_datetime(data.find('d:ScheduleTime', ns).text)
 
         
          
            df1.loc[len(df1) +1] = [applicable_at,name, value,created_date]