import xml.etree.ElementTree as ET #pretty print method def indent(elem, level=0): i = "\n" + level*" " j = "\n" + (level-1)*" " if len(elem): if not elem.text or not elem.text.strip(): elem.text = i + " " if not elem.tail or not elem.tail.strip(): elem.tail = i for subelem in elem: indent(subelem, level+1) if not elem.tail or not elem.tail.strip(): elem.tail = j else: if level and (not elem.tail or not elem.tail.strip()): elem.tail = j return elem tree = ET.parse('bookstore2.xml') root = tree.getroot() #update all price for price in root.iter('price'): new_price = int(price.text) + 5 price.text = str(new_price) price.set('updated', 'yes') #write to file tree = ET.ElementTree(indent(root)) tree.write('bookstore2.xml', xml_declaration=True, encoding='utf-8')