Comparing two xml files in python

Question

I am new to programming in python,´and i have some troubles understanding the concept. I wish to compare two xml files. These xml files are quite large. I will give an examp

Answer 1

My approach to the problem was transforming each XML into a xml.etree.ElementTree and iterating through each of the layers. I also included the functionality to ignore a list of attributes while doing the comparison.

The first block of code holds the class used:

import xml.etree.ElementTree as ET
import logging

class XmlTree():

    def __init__(self):
        self.hdlr = logging.FileHandler('xml-comparison.log')
        self.formatter = logging.Formatter('%(asctime)s %(levelname)s %(message)s')

    @staticmethod
    def convert_string_to_tree( xmlString):

        return ET.fromstring(xmlString)

    def xml_compare(self, x1, x2, excludes=[]):
        """
        Compares two xml etrees
        :param x1: the first tree
        :param x2: the second tree
        :param excludes: list of string of attributes to exclude from comparison
        :return:
            True if both files match
        """

        if x1.tag != x2.tag:
            self.logger.debug('Tags do not match: %s and %s' % (x1.tag, x2.tag))
            return False
        for name, value in x1.attrib.items():
            if not name in excludes:
                if x2.attrib.get(name) != value:
                    self.logger.debug('Attributes do not match: %s=%r, %s=%r'
                                 % (name, value, name, x2.attrib.get(name)))
                    return False
        for name in x2.attrib.keys():
            if not name in excludes:
                if name not in x1.attrib:
                    self.logger.debug('x2 has an attribute x1 is missing: %s'
                                 % name)
                    return False
        if not self.text_compare(x1.text, x2.text):
            self.logger.debug('text: %r != %r' % (x1.text, x2.text))
            return False
        if not self.text_compare(x1.tail, x2.tail):
            self.logger.debug('tail: %r != %r' % (x1.tail, x2.tail))
            return False
        cl1 = x1.getchildren()
        cl2 = x2.getchildren()
        if len(cl1) != len(cl2):
            self.logger.debug('children length differs, %i != %i'
                         % (len(cl1), len(cl2)))
            return False
        i = 0
        for c1, c2 in zip(cl1, cl2):
            i += 1
            if not c1.tag in excludes:
                if not self.xml_compare(c1, c2, excludes):
                    self.logger.debug('children %i do not match: %s'
                                 % (i, c1.tag))
                    return False
        return True

    def text_compare(self, t1, t2):
        """
        Compare two text strings
        :param t1: text one
        :param t2: text two
        :return:
            True if a match
        """
        if not t1 and not t2:
            return True
        if t1 == '*' or t2 == '*':
            return True
        return (t1 or '').strip() == (t2 or '').strip()

The second block of code holds a couple of XML examples and their comparison:

xml1 = "ToveJaniReminderDon't forget me this weekend!"

xml2 = "ToveDanielReminderDon't forget me this weekend!"

tree1 = XmlTree.convert_string_to_tree(xml1)
tree2 = XmlTree.convert_string_to_tree(xml2)

comparator = XmlTree()

if comparator.xml_compare(tree1, tree2, ["from"]):
    print "XMLs match"
else:
    print "XMLs don't match"

Most of the credit for this code must be given to syawar