# Copyright (C) Boris Kats 2011 - 2012. import sys, string from xml.dom import minidom, Node from datetime import date from datetime import datetime as dt #import types from types import * import collections from keyword import iskeyword as iskeyword __xmlspecial__= collections.OrderedDict([("&","&"),("<","<"),(">",">"),('"',""")]) __TupleLimit__ = 5 def strToXMLstr(word,table = __xmlspecial__): for i, j in table.items() : word = word.replace(i,j) return word def XMLstrTostr(word,table = __xmlspecial__): for i, j in table.items() : word = word.replace(j,i) return word def make_date(d): ''' ugly fuction to handle all kind of date formats as ("02-03-2012","01-FEB-12","01/23/12","11/28/06") which are used simultaneously by US Department of Treasure ''' index = d.find('T') if index != -1: d = d[:index] if '-' in d: parts = d.split('-') dt_type='-' else: parts = d.split('/') dt_type = '/' if parts[1].isalpha(): month_f ='%b' if len(parts[1])==3 else '%B' first_f ='%d' second_f = '%Y' if len(parts[2])==4 else '%y' else: if int(parts[0])<=12: first_f = '%m' month_f = '%d' second_f = '%Y' if len(parts[2])==4 else '%y' else: if int(parts[0]) > 1000: first_f = '%Y' month_f = '%m' second_f = '%d' else: first_f = '%m' month_f = '%d' second_f = '%Y' if len(parts[2])==4 else '%y' d_format = dt_type.join([name for name in [first_f,month_f,second_f] ]) return dt.strptime(d,d_format).date() def make_bool(boolean): if boolean.isalpha(): return boolean.upper()=='TRUE' else: return boolean !='0' class anyxml(object): '''The class, which populate himself from xml recursivly into ready to use python class. The types of primitives will be deduced from xml as string representation of primitive. For example in xml:
27MystreetTrue 2012-01-120.75>...
"27" will became "int"; "0.75" => "float; "Mystreet" => str, "True" => bool and "2012-01-12" => date. All attempts are made to preserve information about tags (names) from xml. For example above the resultant python class will have var Address as namedtuple with members HomeNumber, Street ... and each of those members in turn will be instances of proper type and ready to use. The couple of other samples: xml: 0.1 .... 0.9 will came out in python class as MyVector as list of floats; xml: <1Month>0.25<2Month>0.35.... will be translated into var myMap as dictionary of string and float or into namedtuple, based by length of array. The class will accept any xml with simple rules ( nothing unreasonable): a) All elements should be valid xml : I am string or b) Empty elements as will be ignored c) Empty wrappers as will be ignored as well - tag "MyElement" in that context does not carry any usefull information. d) Elements of collection types should be bracked; otherwise the name of collection is unknown: 0.5 0.6 .... 0.7 The name myVector (type of list) will come to python class; however tag names for elements of containers are irrelevant: they are nameless and accessible by [] operator. The containers with distinguished tags will be translated into dict or namedtuple to preserve these names. The types of dict and namedtuple are interchangeable; however if the sequence is homogeneous(all elements have the same type), it will translated into the dict. Sequences with mixed types of elements will be accepted in pythonic style. If for some irregularity in xml, names of elements were lost in translation process, the warning message will be produced. Often xml is coming from thrird party application with it's own namespaces and problems. It is not practical to deal with unreasonable of xml in that class. That problem can be addressed with pre-processing of input xml as : 1. make the special dictionary to translate input xml into something reasonable: 2. read xml into single string and translate it with function strToXMLstr(xml,table= translator) 3. feed minidom parser with that string instead of file ( use doc = minidom.parseString(data) ). Hopefully, this pre-processing procedure will help. In the real life example the xml from US Department of Treasure is used to generate US Treasure Yield Curve. The xml itself, fetched from url, is in terrible condition: meaningless names, all kind of date formats("02-03-2012","01-FEB-12","01/23/12","11/28/06" are used simultaneously, tag names contain punctuations symbols, etc ...( This is the reason for ugly function make_date). Actually, there are two different urls with two xml schemas and for historical datum xml is not normalized at all: the sequence of tags with the same names are not bracketed. However, it is still possible to convert that xml into reasonable python class. The historical xml contains the information for full year and it runs a little bit longer. Run appliation as "python anyxml.py 02/07/2012" or for any business date in the past. To inspect the content of resultant object one can use nice function "total_size" in verbose mode by Raymond Hettinger from http://code.activestate.com/recipes/577504/ or function objwalk by Yaniv Aknin from: http://code.activestate.com/recipes/577982/. Before using that class make sure that your input xml is valid: try to open it in browser. ''' def __init__(self,source): super() doc = minidom.parseString(source) self.buildFromXml(doc.documentElement) def fromStringToType(self,content): ''' Making rhe guess what is the type of data ''' if content.isalpha(): contentUp = content.upper() if contentUp=='TRUE' or contentUp=='FALSE': return make_bool(content) return content else: index = content.find('T') input = content[:index] if index != -1 else content components = input.split('-') if '-' in input else input.split('/') if (8<=len(input)<= 10) and len(components) == 3: return make_date(content) else: try: try_int = int(content) return try_int except ValueError: try: try_flt = float(content) return try_flt except ValueError: return content def getAttribute(self,node,attribute): ''' get attribute in safe mode ''' if node.nodeType != Node.ELEMENT_NODE: return None if hasattr(node,'attributes'): attributes = node.attributes if hasattr(attributes,'get'): item = attributes.get(attribute,None) if item and len(item.value.strip()) != 0: return item.value.strip() else: return None else: return None else: return None def buildFromXml(self,root): ''' travel int xml tree ''' for node in root.childNodes: nodeKind = node.nodeType if nodeKind == Node.ELEMENT_NODE: nodeName = node.nodeName.strip() item = self.buildNode(node) if item[1] != None: #for regulars xml setattr(self,item[0],item[1]) will work #for irregulars put element into wrappre list modName = item[0] + 'List_' items = getattr(self,modName,None) if items != None: items.append(item[1]) else: items = list() items.append(item[1]) setattr(self,modName,items) #get rid of artificial lists membersList = [member for member in dir(self) if member.endswith('List_')] for member in membersList: element = getattr(self, member) if(type(element) == list and len(element) ==1): item = element[0] delattr(self,member) setattr(self,member[:-5],item) def nodecount(self,root,justElements = True): ''' just to enumerate nodes ''' if not justElements: return len(root.childNodes) count = 0 for child in root.childNodes: if child.nodeType == Node.ELEMENT_NODE: count +=1 return count def buildNode(self,root): ''' just to retrieve node(tag) name and it's content ''' rootName = root.nodeName.strip() size = len(root.childNodes) if size == 0: value = self.getAttribute(root,'value') if value: return rootName,self.fromStringToType(value) else: return rootName,None else: if size ==1: child = root.childNodes[0] if child.nodeType == Node.TEXT_NODE: value = child.nodeValue.strip() if len(value)==0: return rootName,None else: return rootName,self.fromStringToType(value) else: internal = self.buildNode(child) return internal else: size = self.nodecount(root) if (size ==1): #just empty wrapper for kid in root.childNodes: if kid.nodeType == Node.ELEMENT_NODE: internal = self.buildNode(kid) return internal items = list() names = list() for kid in root.childNodes: item = self.buildNode(kid) if item[1] != None: items.append(item[1]) name = item[0] if name.find(':') !=-1 : name = name.replace(':','_') if iskeyword(name): name = name[:1].upper()+ name[1:] if not name in names: names.append(name) return self.transform(rootName, names,items) def transform(self,rootName, names,items): ''' Transform two input lists of names and values into class member of list, dict, namedtuple or tuple.''' isHomogeneous = True tt = type(items[0]) if (tt == int): tt = float for el in items[:1]: ttn = type(el) if (ttn == int): ttn = float if tt != ttn : isHomogeneous = False break if ( len(names) ==1 and isHomogeneous): member = items[0] if (type(member).__name__ == 'namedtuple' and len(member)==2 and hash(member[0])): myitems = dict() # dict for member in items: myitems[member[0]] = member[1] return rootName,myitems return rootName,items # list if (len(names) == len(items)): if isHomogeneous and len(items) > __TupleLimit__ : myitems = dict() #dict count = 0 for member in items: myitems[names[count]] = member count +=1 return rootName,myitems else: # named tuple tupleNames = ' '.join([name for name in names]) Temp = collections.namedtuple('namedtuple',tupleNames) return rootName,Temp(*items) message = 'some information about names is lost due to irregular xml in: ' + rootName +'\n' warnings = getattr(self,'warnings',None) if (warnings == None): warnings = message setattr(self,'warnings',warnings) else: warnings = warnings + message if len(items) > __TupleLimit__ : return rootName,items else: return rootName,tuple(items) if __name__ =='__main__': import urllib.request import sys,time args = sys.argv[1:] try: inputDate = dt.strptime(args[0], '%m/%d/%Y').date() except ValueError as err: print(err) sys.exit(-1) today = date.today() if ( inputDate > today): print('Error:Input date should be business date in the past or today after 6:00PM') sys.exit(-1) url_g ='http://www.treasury.gov/resource-center/data-chart-center/interest-rates/' url_1 ='Datasets/yield.xml' url_2 ='pages/XmlView.aspx?data=yieldyear&year=' usingHistory = False if (inputDate.year != today.year or inputDate.month !=today.month): usingHistory = True url = url_g + url_2+str(inputDate.year) else: url = url_g + url_1 t1 = time.clock() urlfile = urllib.request.urlopen(url) data = urlfile.read().decode("utf8") urlfile.close() t2 = time.clock() print('read data from url elapsed time:',round(t2-t1,4)) myclass = anyxml(data) warnings = getattr(myclass,'warnings',None) if warnings: print(warnings) curveFound = False class FoundCurve(Exception): pass if ( not usingHistory): try: for list_of_week in myclass.LIST_G_WEEK_OF_MONTH: if 'LIST_G_NEW_DATE' in list_of_week.keys(): for date_of_week in list_of_week['LIST_G_NEW_DATE']: if(date_of_week.BID_CURVE_DATE == inputDate): curveFound = True print("{} {} {}".format('For',inputDate,'US Treasure Curve is:')) print('Tenor Yield') tbl = date_of_week.G_BC_CAT for k, v in tbl.items(): if (k.find('DISPLAY') == -1): print(k[3:], "{}{}".format(v,'%')) raise FoundCurve() except FoundCurve: pass else: for entry in myclass.entryList_: tbl = entry.m_properties if tbl['d_NEW_DATE'] == inputDate: curveFound = True print("{} {} {}".format('For',inputDate,'US Treasure Curve is:')) print('Tenor Yield') for k,v in tbl.items(): if k.find('_BC_') !=-1 and k.find('DISPLAY') == -1: print(k[5:],"{0}{1}".format(round(v,4),'%')) break if not curveFound: print('For',inputDate,'US Treasure Curve not found: is it business date?') print("anyxml elapsed time:",round(time.clock()-t2,4))