parser un fichier xml avec xml.sax

Version imprimable

BOnjour à tous,

je viens vers vous pour soliciter votre aide sur un parsing de fichier xml... En effet, je me heurte à quelques problématiques, à savoir:
je n'arrive pas à récupérer certainnes informations, commme la description, l'année et les images.
mon fichier xml est le suivant:

Citation:

<?xml version="1.0" encoding="utf-8"?> <xml> <ad>
<id><![CDATA[1]]></id> <title><![CDATA[Jaguar XKR]]></title>
<url><![CDATA[link]]></url> <content><![CDATA[Jaguar XKR
skqlmskmlqskml qpdqsdkqmlkdmlq qdmlkqsmldkdqsklqsml]]></content>
<price currency="US"><![CDATA[4000.00]]></price>
<city><![CDATA[Tokyo]]></city>
<postcode><![CDATA[92200]]></postcode>
<date><![CDATA[2013-10-01]]></date>
<expiration_date><![CDATA[2017-02-27]]></expiration_date>

<year><![CDATA[2008]]></year> <make><![CDATA[Jaguar]]></make>
<model><![CDATA[Xkr]]></model> <fuel><![CDATA[fuel]]></fuel>
<mileage><![CDATA[68000]]></mileage>
<transmission><![CDATA[Automatique]]></transmission>
<power><![CDATA[12]]></power> <pictures>
<picture><picture_url><![CDATA[link1]]></picture_url></picture>
<picture><picture_url><![CDATA[link2]]></picture_url></picture>
</pictures> </ad>

mon code python est le suivant:

Code:

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#!/usr/bin/python
 
import xml.sax
 
class MovieHandler( xml.sax.ContentHandler ):
   def __init__(self):
      self.CurrentData = ""
      self.title = ""
      self.url = ""
      self.description = ""
      self.price = ""
      self.city = ""
      self.postcode = ""
      self.year = ""
      self.date = ""
      self.expiration_date =  ""
      self.brand = ""
      self.model = ""
      self.fuel = ""
      self.mileage = ""
      self.transmission = ""
      self.power = ""
      self.picture =  ""
 
 
   # Call when an element starts
   def startElement(self, tag, attributes):
      self.CurrentData = tag
 
   # Call when an elements ends
   def endElement(self, tag):
      if self.CurrentData == "title":
         print "Title:", self.title
      elif self.CurrentData == "url":
         print "Url:", self.url
      elif self.CurrentData == "content":
         print "Description:", self.description
      elif self.CurrentData == "price":
         print "price:", self.price
      elif self.CurrentData == "city":
         print "City:", self.city
      elif self.CurrentData == "postcode":
         print "Postcode:", self.postcode
      elif self.CurrentData == "date":
         print "Date:", self.date
      elif self.CurrentData == "expiration_date":
         print "expiration date:", self.expiration_date
      elif self.CurrentData == "year":
         print "year:", self.year
      '''
      elif self.CurrentData == "make":
         print "Brand:", self.brand
      elif self.CurrentData == "model":
         print "Model:", self.model
      self.CurrentData = ""
      '''
   # Call when a character is read
   def characters(self, content):
      if self.CurrentData == "title":
         self.title = content
      elif self.CurrentData == "url":
         self.url = content
      elif self.CurrentData == "content":
         self.description = content
      elif self.CurrentData == "price":
         self.price = content
      elif self.CurrentData == "city":
         self.city = content
      elif self.CurrentData == "postcode":
         self.postcode = content
      elif self.CurrentData == "date":
         self.date = content
      elif self.CurrentData == "expiration_date":
         self.expiration_date = content
      elif self.CurrentData == "year":
         self.year = content
      '''
      elif self.CurrentData == "make":
         self.brand = content
      elif self.CurrentData == "model":
         self.model = content
       '''
 
 
if ( __name__ == "__main__"):
 
   # create an XMLReader
   parser = xml.sax.make_parser()
   # turn off namepsaces
   parser.setFeature(xml.sax.handler.feature_namespaces, 0)
 
   # override the default ContextHandler
   Handler = MovieHandler()
   parser.setContentHandler( Handler )
 
   parser.parse("myfile.xml")

comment puis-je lire ces balises ?
Merci d'avance.

Salut,

Simplifions:

Code:

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#!/usr/bin/python
 
import xml.sax
 
class MovieHandler( xml.sax.ContentHandler ):
    def __init__(self):
        self.CurrentData = ""
        self.cars = []
        self.current_car = None
 
    def create_new_car(self):
        self.current_car = {}
 
    # Call when an element starts
    def startElement(self, tag, attributes):
        print "startElement", tag, attributes
        if tag == "xml":
            return
        elif tag == "ad":
            self.create_new_car()
 
        self.CurrentData = tag
 
    # Call when an elements ends
    def endElement(self, tag):
        if self.CurrentData:
            print " %s: %s" %(self.CurrentData, self.current_car[self.CurrentData])
 
        if tag == "ad":
            self.cars.append(self.current_car)
        self.CurrentData = ""
 
    # Call when a character is read
    def characters(self, content):
        if not self.CurrentData or not content:
            return
 
        self.current_car[self.CurrentData] = content
 
 
if ( __name__ == "__main__"):
 
    # create an XMLReader
    parser = xml.sax.make_parser()
    # turn off namepsaces
    parser.setFeature(xml.sax.handler.feature_namespaces, 0)
 
    # override the default ContextHandler
    Handler = MovieHandler()
    parser.setContentHandler( Handler )
 
    parser.parse("car.xml")
    print Handler.cars

Commentaire: sacrement ch..t les indentations de trois caractères

Citation:

Envoyé par pi-2r

BOnjour à tous,
comment puis-je lire ces balises ?
Merci d'avance.

Bonjour,

Avec les données suivantes (à mettre dans un fichier my_file.xml :

Code:

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<?xml version="1.0" encoding="utf-8"?>
<xml>
    <ad>
        <id><![CDATA[1]]></id>
        <title><![CDATA[Jaguar XKR]]></title>
        <url><![CDATA[link]]></url>
        <content><![CDATA[Jaguar XKR skqlmskmlqskml qpdqsdkqmlkdmlq qdmlkqsmldkdqsklqsml]]></content>
        <price currency="USD"><![CDATA[4000.00]]></price>
        <city><![CDATA[Tokyo]]></city>
        <postcode><![CDATA[92200]]></postcode>
        <date><![CDATA[2013-10-01]]></date>
        <expiration_date><![CDATA[2017-02-27]]></expiration_date>
        <year><![CDATA[2008]]></year>
        <make><![CDATA[Jaguar]]></make>
        <model><![CDATA[Xkr]]></model>
        <fuel><![CDATA[fuel]]></fuel>
        <mileage><![CDATA[68000]]></mileage>
        <transmission><![CDATA[Automatique]]></transmission>
        <power><![CDATA[12]]></power>
        <pictures group="banners">
            <picture name="super car !">
                <picture_url><![CDATA[link1]]></picture_url>
            </picture>
            <picture>
                <picture_url><![CDATA[link2]]></picture_url>
            </picture>
        </pictures>
    </ad>
</xml>

Testez le code suivant :

Code:

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#!/usr/bin/env python
# -*- coding: utf-8 -*-
 
from __future__ import unicode_literals
 
import xml.sax
 
class Element:
    def __init__ (self, tag, attributes):
        self.tag = str(tag)
        self.attributes = attributes
        self.cdata = ""
        self.children = []
    # end def
# end class
 
class DataContentHandler (xml.sax.ContentHandler):
 
    def __init__ (self):
        self.parents = []
        self.root_node = None
    # end def
 
    def startElement (self, tag, attributes):
        "opening XML element tag"
        # element inits
        element = Element(tag, attributes)
        # element is root node ?
        if not self.parents:
            self.root_node = element
            self.parents.append(self.root_node)
        # child element
        else:
            # get last registered parent element
            parent = self.parents[-1]
            # add new child element to parent element
            parent.children.append(element)
            # now child element becomes
            # a potential parent for
            # further children elements
            self.parents.append(element)
        # end if
    # end def
 
    def endElement (self, tag):
        "closing XML element tag"
        # pop last registered parent from LIFO stack
        if self.parents:
            self.parents.pop(-1)
        # end if
    # end def
 
    def characters (self, content):
        "CDATA encountered on the run"
        # get last registered parent element
        parent = self.parents[-1]
        # add CDATA char string to this element
        parent.cdata = str(content).strip() # strip useless chars
    # end def
 
    def dump (self, element=None, show_all=False):
        "showing element's contents"
        # got no initial element?
        if not element:
            # set to root node
            element = self.root_node
        # end if
        # browse element's children
        for child in element.children:
            # shortcut inits
            _tag = child.tag.capitalize()
            _attrs = child.attributes
            # print tag and cdata only
            if show_all or child.cdata:
                print "{0}: '{1}'".format(_tag, child.cdata)
            # print tag if got some attrs to show up
            elif _attrs.getLength():
                print "{0}:".format(_tag)
            # end if
            # showing attributes
            for attribute in _attrs.getNames():
                print " |---> {0}: '{1}'"\
                    .format(attribute, _attrs.getValue(attribute))
            # end for
            # then recursively dump child's children and so on
            self.dump(child, show_all)
        # end for
    # end def
# end class DataContentHandler
 
if __name__ == "__main__":
 
    # handler init
    handler = DataContentHandler()
 
    # parsing file
    xml.sax.parse("my_file.xml", handler)
 
    # change 'show_all' flag
    # to meet your needs (True or False)
    handler.dump(show_all=True)
 
# end if

Note : les balises CDATA ne sont vraiment utiles que là où vous craignez des injections XML, ce n'est donc pas la peine d'en mettre partout (sauf si le fichier XML est généré par un automate).

Note 2 : le module xml.sax est plutôt destiné aux personnes qui cherchent à implémenter un analyseur de type de document plutôt que des données XML.
Ici, j'ai émulé un analyseur de données XML, mais il serait plus sage de regarder du côté de xml.etree.ElementTree pour le dépiautage facile de données XML dans une arborescence : https://docs.python.org/3/library/xm...ementtree.html

Exercice formateur et intéressant, au demeurant. :mrgreen: ;)

@+.