removed datafiles

<!-- DTD for auction database -->

<!-- $Id: auction.dtd,v 1.15 2001/01/29 21:42:35 albrecht Exp $ -->

<!ELEMENT site            (regions, categories, catgraph, people, open_auctions, closed_auctions)>

<!ELEMENT categories      (category+)>

<!ELEMENT category        (name, description)>

<!ATTLIST category        id ID #REQUIRED>

<!ELEMENT name            (#PCDATA)>

<!ELEMENT description     (text | parlist)>

<!ELEMENT text            (#PCDATA | bold | keyword | emph)*>

<!ELEMENT bold		  (#PCDATA | bold | keyword | emph)*>

<!ELEMENT keyword	  (#PCDATA | bold | keyword | emph)*>

<!ELEMENT emph		  (#PCDATA | bold | keyword | emph)*>

<!ELEMENT parlist	  (listitem)*>

<!ELEMENT listitem        (text | parlist)*>

<!ELEMENT catgraph        (edge*)>

<!ELEMENT edge            EMPTY>

<!ATTLIST edge            from IDREF #REQUIRED to IDREF #REQUIRED>

<!ELEMENT regions         (africa, asia, australia, europe, namerica, samerica)>

<!ELEMENT africa          (item*)>

<!ELEMENT asia            (item*)>

<!ELEMENT australia       (item*)>

<!ELEMENT namerica        (item*)>

<!ELEMENT samerica        (item*)>

<!ELEMENT europe          (item*)>

<!ELEMENT item            (location, quantity, name, payment, description, shipping, incategory+, mailbox)>

<!ATTLIST item            id ID #REQUIRED

                          featured CDATA #IMPLIED>

<!ELEMENT location        (#PCDATA)>

<!ELEMENT quantity        (#PCDATA)>

<!ELEMENT payment         (#PCDATA)>

<!ELEMENT shipping        (#PCDATA)>

<!ELEMENT reserve         (#PCDATA)>

<!ELEMENT incategory      EMPTY>

<!ATTLIST incategory      category IDREF #REQUIRED>

<!ELEMENT mailbox         (mail*)>

<!ELEMENT mail            (from, to, date, text)>

<!ELEMENT from            (#PCDATA)>

<!ELEMENT to              (#PCDATA)>

<!ELEMENT date            (#PCDATA)>

<!ELEMENT itemref         EMPTY>

<!ATTLIST itemref         item IDREF #REQUIRED>

<!ELEMENT personref       EMPTY>

<!ATTLIST personref       person IDREF #REQUIRED>

<!ELEMENT people          (person*)>

<!ELEMENT person          (name, emailaddress, phone?, address?, homepage?, creditcard?, profile?, watches?)>

<!ATTLIST person          id ID #REQUIRED>

<!ELEMENT emailaddress    (#PCDATA)>

<!ELEMENT phone           (#PCDATA)>

<!ELEMENT address         (street, city, country, province?, zipcode)>

<!ELEMENT street          (#PCDATA)>

<!ELEMENT city            (#PCDATA)>

<!ELEMENT province        (#PCDATA)>

<!ELEMENT zipcode         (#PCDATA)>

<!ELEMENT country         (#PCDATA)>

<!ELEMENT homepage        (#PCDATA)>

<!ELEMENT creditcard      (#PCDATA)>

<!ELEMENT profile         (interest*, education?, gender?, business, age?)>

<!ATTLIST profile         income CDATA #IMPLIED>

<!ELEMENT interest        EMPTY>

<!ATTLIST interest        category IDREF #REQUIRED>

<!ELEMENT education       (#PCDATA)>

<!ELEMENT income          (#PCDATA)>

<!ELEMENT gender          (#PCDATA)>

<!ELEMENT business        (#PCDATA)>

<!ELEMENT age             (#PCDATA)>

<!ELEMENT watches         (watch*)>

<!ELEMENT watch           EMPTY>

<!ATTLIST watch           open_auction IDREF #REQUIRED>

<!ELEMENT open_auctions   (open_auction*)>

<!ELEMENT open_auction    (initial, reserve?, bidder*, current, privacy?, itemref, seller, annotation, quantity, type, interval)>

<!ATTLIST open_auction    id ID #REQUIRED>

<!ELEMENT privacy         (#PCDATA)>

<!ELEMENT initial         (#PCDATA)>

<!ELEMENT bidder          (date, time, personref, increase)>

<!ELEMENT seller          EMPTY>

<!ATTLIST seller          person IDREF #REQUIRED>

<!ELEMENT current         (#PCDATA)>

<!ELEMENT increase        (#PCDATA)>

<!ELEMENT type            (#PCDATA)>

<!ELEMENT interval        (start, end)>

<!ELEMENT start           (#PCDATA)>

<!ELEMENT end             (#PCDATA)>

<!ELEMENT time            (#PCDATA)>

<!ELEMENT status          (#PCDATA)>

<!ELEMENT amount          (#PCDATA)>

<!ELEMENT closed_auctions (closed_auction*)>

<!ELEMENT closed_auction  (seller, buyer, itemref, price, date, quantity, type, annotation?)>

<!ELEMENT buyer           EMPTY>

<!ATTLIST buyer           person IDREF #REQUIRED>

<!ELEMENT price           (#PCDATA)>

<!ELEMENT annotation      (author, description?, happiness)>

<!ELEMENT author          EMPTY>

<!ATTLIST author          person IDREF #REQUIRED>

<!ELEMENT happiness       (#PCDATA)>

from lxml import etree

import lxml.sax

from xml.sax.handler import ContentHandler

# This class implements the sax-like events for converting XML elemnts into

# bracket-notation nodes and labels.

class XMarkContentHandler(ContentHandler):

    def __init__(self):

        self.bn = ""

    # Open tag.

    def startElementNS(self, name, qname, attributes):

        uri, localname = name

        self.bn += "{" + localname

        d = dict(attributes)

        # Sort the attributes by their keys.

        for key, value in sorted(d.items(), key = lambda element : element[0][1]):

            self.bn += "{" + key[1].translate(str.maketrans({"{":  r"\{",

                                          "}":  r"\}",

                                          "\\": r"\\"})) + "{" + value.translate(str.maketrans({"{":  r"\{",

                                          "}":  r"\}",

                                          "\\": r"\\"})) + "}}"

    # Close tag.

    def endElementNS(self, name, qname):

        self.bn += "}"

    # Tag content.

    def characters(self, data):

        self.bn += "{" + data.translate(str.maketrans({"{":  r"\{",

                                          "}":  r"\}",

                                          "\\": r"\\"})) + "}"

print("--- Loading XMARK dataset.")

xmark_parser = etree.XMLParser(load_dtd=True, remove_blank_text=True)

xmark_data_tree = etree.parse('standard', xmark_parser)

root = xmark_data_tree.getroot()

# Output files.

xmark_bracket = open('xmark.bracket', 'w')

print("--- Processing each child of xmark's root.")

tree_id = 0

for child in root:

    tree_id += 1

    # Printing simple progress.

    if tree_id % 10000 == 0:

        print("- Tree %s" % (tree_id))

    handler = XMarkContentHandler()

    lxml.sax.saxify(child, handler)

    xmark_bracket.write(handler.bn + "\n")

print("--- Closing output files.")

xmark_bracket.close()