Find missing/added elements in 2 XML files

XMLdiff.py

import os
import xml.etree.ElementTree as ET
import difflib

dataA = []
dataB = []
f = []

for subdir, dirs, files in os.walk(os.getcwd()):
    for file in files:
        if '.xml' in file:
            f.append(file)

if len(f) > 2:
    print("\nMore than 2 .XML files present!\n")
    exit(0)
    
root = ET.parse(f[0]).getroot()
for elem in root.iter():
    dataA.append(elem.tag)
root = ET.parse(f[1]).getroot()
for elem in root.iter():
    dataB.append(elem.tag)

diff = difflib.Differ().compare(dataA, dataB)
print ('\n'.join(diff))