Python XML Parser

In our project we had kept the operations rules as an XML and the below mentioned parser was used to get the conditions to be applied for each operation.

The xml.dom.minidom was used to parse the xml file and return a document object .The document object was used to obtain the child nodes and for each child nodes the corresponding fileds and attributes were retrieved using the get attribute method and appended as a tuple.

The tuple was then included in the dictionary with the nodename as the key.

 import xml.dom.minidom

class XMLParser:
    def __init__(self, filePath):
        self.xml_file_path = filePath

    def get_a_document(self):
        return xml.dom.minidom.parse(self.xml_file_path)

    def process_xml_return_dict(self):
        doc = self.get_a_document()
        fieldMapping = doc.childNodes[0]
        operations = {}
        for layer in fieldMapping.childNodes:
            if layer.nodeType == xml.dom.minidom.Node.TEXT_NODE or layer.nodeType == xml.dom.minidom.Node.COMMENT_NODE:
                continue
            fieldList = self.get_fields(layer)
            attrList = self.get_attributes(layer)
            operations[layer.nodeName] = (attrList, fieldList)
        return operations

    def get_attributes(self, node):
        attrList = []
        nodeMap = node.attributes
        for index in range(nodeMap.length):
            attrName = nodeMap.item(index).name
            attrValue = node.getAttribute(attrName)
            attrList.append((attrName, attrValue))
        return attrList

    def get_fields(self, node):
        fieldList = []
        for childNode in node.childNodes:
            if childNode.nodeType != xml.dom.minidom.Node.TEXT_NODE and childNode.nodeType != xml.dom.minidom.Node.COMMENT_NODE:
                fromField = childNode.getAttribute('FromField')
                toField = childNode.getAttribute('ToField')
                fieldValue = childNode.getAttribute('Value')
                condition = childNode.getAttribute('Condition')
                fieldList.append((fromField, toField, fieldValue, condition))
        return fieldList
Python pickle module & Zip file creation
 
Description
The solution gives a solution to use the pickle module and to create a Zip File.  
 
 # below is a typical Python dictionary object of roman numerals
 romanD1 = {'I':1,'II':2,'III':3,'IV':4,'V':5,'VI':6,'VII':7,'VIII':8,'IX':9,'X':10}
  
 # to save a Python object like a dictionary to a file
 # and load it back intact you have to use the pickle module
 import pickle
 print "The original dictionary:"
 print romanD1
 file = open("roman1.dat", "w")
 pickle.dump(romanD1, file)
 file.close()
 # now load the dictionay object back from the file ...
 file = open("roman1.dat", "r")
 romanD2 = pickle.load(file)
 file.close()
 print "Dictionary after pickle.dump() and pickle.load():"
 print romanD2

 # for large text files you can write and read a zipped file (PKZIP format)
 # notice that the syntax is mildly different from normal file read/write
 import zipfile
 zfilename = "English101.zip"
 zout = zipfile.ZipFile(zfilename, "w")
 zout.writestr(zfilename, str1 + str2)
 zout.close()
 # read the zipped file back in
 zin = zipfile.ZipFile(zfilename, "r")
 strz = zin.read(zfilename)
 zin.close()
 print "Testing the contents of %s:" % zfilename
 print strz