"""\A library of useful helper classes to the SAX classes, for theconvenience of application and driver writers.""" import os, urlparse, urllib, typesimport handlerimport xmlreader try:    _StringTypes = [types.StringType, types.UnicodeType]except AttributeError:    _StringTypes = [types.StringType] # See whether the xmlcharrefreplace error handler is# supportedtry:    from codecs import xmlcharrefreplace_errors    _error_handling = "xmlcharrefreplace"    del xmlcharrefreplace_errorsexcept ImportError:    _error_handling = "strict" def __dict_replace(s, d):    """Replace substrings of a string using a dictionary."""    for key, value in d.items():        s = s.replace(key, value)    return s def escape(data, entities={}):    """Escape &, <, and > in a string of data.     You can escape other strings of data by passing a dictionary as    the optional entities parameter.  The keys and values must all be    strings; each key will be replaced with its corresponding value.    """     # must do ampersand first    data = data.replace("&", "&amp;")    data = data.replace(">", "&gt;")    data = data.replace("<", "&lt;")    if entities:        data = __dict_replace(data, entities)    return data def unescape(data, entities={}):    """Unescape &amp;, &lt;, and &gt; in a string of data.     You can unescape other strings of data by passing a dictionary as    the optional entities parameter.  The keys and values must all be    strings; each key will be replaced with its corresponding value.    """    data = data.replace("&lt;", "<")    data = data.replace("&gt;", ">")    if entities:        data = __dict_replace(data, entities)    # must do ampersand last    return data.replace("&amp;", "&") def quoteattr(data, entities={}):    """Escape and quote an attribute value.     Escape &, <, and > in a string of data, then quote it for use as    an attribute value.  The \" character will be escaped as well, if    necessary.     You can escape other strings of data by passing a dictionary as    the optional entities parameter.  The keys and values must all be    strings; each key will be replaced with its corresponding value.    """    entities = entities.copy()    entities.update({'\n': '&#10;', '\r': '&#13;', '\t':'&#9;'})    data = escape(data, entities)    if '"' in data:        if "'" in data:            data = '"%s"' % data.replace('"', "&quot;")        else:            data = "'%s'" % data    else:        data = '"%s"' % data    return data  class XMLGenerator(handler.ContentHandler):     def __init__(self, out=None, encoding="iso-8859-1"):        if out is None:            import sys            out = sys.stdout        handler.ContentHandler.__init__(self)        self._out = out        self._ns_contexts = [{}] # contains uri -> prefix dicts        self._current_context = self._ns_contexts[-1]        self._undeclared_ns_maps = []        self._encoding = encoding     def _write(self, text):        if isinstance(text, str):            self._out.write(text)        else:            self._out.write(text.encode(self._encoding, _error_handling))     def _qname(self, name):        """Builds a qualified name from a (ns_url, localname) pair"""        if name[0]:            # The name is in a non-empty namespace            prefix = self._current_context[name[0]]            if prefix:                # If it is not the default namespace, prepend the prefix                return prefix + ":" + name[1]        # Return the unqualified name        return name[1]     # ContentHandler methods     def startDocument(self):        self._write('<?xml version="1.0" encoding="%s"?>\n' %                        self._encoding)     def startPrefixMapping(self, prefix, uri):        self._ns_contexts.append(self._current_context.copy())        self._current_context[uri] = prefix        self._undeclared_ns_maps.append((prefix, uri))     def endPrefixMapping(self, prefix):        self._current_context = self._ns_contexts[-1]        del self._ns_contexts[-1]     def startElement(self, name, attrs):        self._write('<' + name)        for (name, value) in attrs.items():            self._write(' %s=%s' % (name, quoteattr(value)))        self._write('>')     def endElement(self, name):        self._write('</%s>' % name)     def startElementNS(self, name, qname, attrs):        self._write('<' + self._qname(name))         for prefix, uri in self._undeclared_ns_maps:            if prefix:                self._out.write(' xmlns:%s="%s"' % (prefix, uri))            else:                self._out.write(' xmlns="%s"' % uri)        self._undeclared_ns_maps = []         for (name, value) in attrs.items():            self._write(' %s=%s' % (self._qname(name), quoteattr(value)))        self._write('>')     def endElementNS(self, name, qname):        self._write('</%s>' % self._qname(name))     def characters(self, content):        self._write(escape(content))     def ignorableWhitespace(self, content):        self._write(content)     def processingInstruction(self, target, data):        self._write('<?%s %s?>' % (target, data))  class XMLFilterBase(xmlreader.XMLReader):    """This class is designed to sit between an XMLReader and the    client application's event handlers.  By default, it does nothing    but pass requests up to the reader and events on to the handlers    unmodified, but subclasses can override specific methods to modify    the event stream or the configuration requests as they pass    through."""     def __init__(self, parent = None):        xmlreader.XMLReader.__init__(self)        self._parent = parent     # ErrorHandler methods     def error(self, exception):        self._err_handler.error(exception)     def fatalError(self, exception):        self._err_handler.fatalError(exception)     def warning(self, exception):        self._err_handler.warning(exception)     # ContentHandler methods     def setDocumentLocator(self, locator):        self._cont_handler.setDocumentLocator(locator)     def startDocument(self):        self._cont_handler.startDocument()     def endDocument(self):        self._cont_handler.endDocument()     def startPrefixMapping(self, prefix, uri):        self._cont_handler.startPrefixMapping(prefix, uri)     def endPrefixMapping(self, prefix):        self._cont_handler.endPrefixMapping(prefix)     def startElement(self, name, attrs):        self._cont_handler.startElement(name, attrs)     def endElement(self, name):        self._cont_handler.endElement(name)     def startElementNS(self, name, qname, attrs):        self._cont_handler.startElementNS(name, qname, attrs)     def endElementNS(self, name, qname):        self._cont_handler.endElementNS(name, qname)     def characters(self, content):        self._cont_handler.characters(content)     def ignorableWhitespace(self, chars):        self._cont_handler.ignorableWhitespace(chars)     def processingInstruction(self, target, data):        self._cont_handler.processingInstruction(target, data)     def skippedEntity(self, name):        self._cont_handler.skippedEntity(name)     # DTDHandler methods     def notationDecl(self, name, publicId, systemId):        self._dtd_handler.notationDecl(name, publicId, systemId)     def unparsedEntityDecl(self, name, publicId, systemId, ndata):        self._dtd_handler.unparsedEntityDecl(name, publicId, systemId, ndata)     # EntityResolver methods     def resolveEntity(self, publicId, systemId):        return self._ent_handler.resolveEntity(publicId, systemId)     # XMLReader methods     def parse(self, source):        self._parent.setContentHandler(self)        self._parent.setErrorHandler(self)        self._parent.setEntityResolver(self)        self._parent.setDTDHandler(self)        self._parent.parse(source)     def setLocale(self, locale):        self._parent.setLocale(locale)     def getFeature(self, name):        return self._parent.getFeature(name)     def setFeature(self, name, state):        self._parent.setFeature(name, state)     def getProperty(self, name):        return self._parent.getProperty(name)     def setProperty(self, name, value):        self._parent.setProperty(name, value)     # XMLFilter methods     def getParent(self):        return self._parent     def setParent(self, parent):        self._parent = parent # --- Utility functions def prepare_input_source(source, base = ""):    """This function takes an InputSource and an optional base URL and    returns a fully resolved InputSource object ready for reading."""     if type(source) in _StringTypes:        source = xmlreader.InputSource(source)    elif hasattr(source, "read"):        f = source        source = xmlreader.InputSource()        source.setByteStream(f)        if hasattr(f, "name"):            source.setSystemId(f.name)     if source.getByteStream() is None:        sysid = source.getSystemId()        basehead = os.path.dirname(os.path.normpath(base))        sysidfilename = os.path.join(basehead, sysid)        if os.path.isfile(sysidfilename):            source.setSystemId(sysidfilename)            f = open(sysidfilename, "rb")        else:            source.setSystemId(urlparse.urljoin(base, sysid))            f = urllib.urlopen(source.getSystemId())         source.setByteStream(f)     return source