Busy Autumn

Posted on 20/11/2010, 01:30, by Tomás Vírseda, under News, Semantic Web, Tools.

Right now Vazaar is in standby mode. I haven’t had enough time to code it. Since September three things have took a lot of my time:

  • I’ve came back to the University to study another two years of Information Technology.
  • I’ve started a new public project: WikiNava, which consists on build a wikipedia of my town (Nava de la Asunción, Segovia, Spain). It’s based on Mediawiki and I’m using one of its best extensions: Semantic MediaWiki.
  • Also I am very busy at work. The last three years I’ve been working as a SAP administrator (A very useful IT area if anyone want to work with different Operating Systems, Databases and a very big application which has a lot of subsystems).

I’ve got some petitions to translate Vazaar to other languages but I prefer people wait until I get a polished version. Also I have to finish some modules before release it.

It would be wonderful if I had a new release before Spring.

Tags: , , ,


1 Comment »


~~ · ~~


New custom timeline widget

Posted on 02/09/2010, 03:15, by Tomás Vírseda, under GUI, PyGTK Widgets, Python, SPARQL Queries, Workshop.

Tired of looking for a timeline widget in PyGTK for Vazaar I’ve decided to develop it  by myself.

It’s very simple: 1 calendar and 3 treeviews.

The user clicks a day in the calendar and with the selected date Vazaar asks to the database for those resources created that day, the day before and the day after.

Here is a screenshot:

vazaar-timeline_0

You can find an example in the repository.

Tags: , , , , , , , , ,


3 Comments »


~~ · ~~


How to fix your sqlite database after corruption

Posted on 02/09/2010, 00:45, by Tomás Vírseda, under Python, RDFLib, Workshop.

If you get something like this:

Traceback (most recent call last):
  File "./bin/vazaar", line 79, in
    Vazaar(options, args)
  File "/home/t00m/dev/trunk/vazaarlib/main.py", line 61, in __init__
    self.store = StoreManager(self)
  File "/home/t00m/dev/trunk/vazaarlib/store.py", line 54, in __init__
    self.__get_graph()
  File "/home/t00m/dev/trunk/vazaarlib/store.py", line 85, in __get_graph
    self.graph.store.open(self.options)
  File "/usr/lib/pymodules/python2.6/rdflib/store/Sleepycat.py", line 77, in open
    index.open(index_name, dbname, dbtype, dbopenflags|db.DB_CREATE, dbmode)

MemoryError: (12, 'Cannot allocate memory -- Lock table is out of available locker entries')

Just go to database directory and delete all files similar to __db.

Reason:
This problem occurs when Vazaar accesses the Berkeley database files, it makes temporary locker entries within the tables while it searches for data. If Vazaar crashes often, this issue will occur much sooner because the locks are never cleared.

Tip found at http://www.linuxmaza.com/system-administration/solved-lock-table-is-out-of-available-locker-entries-yum-install-yum-upgrade-3/

Tags: , , , , , , , , , , , , , , , ,


2 Comments »


~~ · ~~


PyGTK XDot Widget

Posted on 19/08/2010, 16:15, by Tomás Vírseda, under GUI, PyGTK Widgets, Python, RDFLib, Tools.

XDot es un magnífico componente para representar grafos interactivos con Python, Graphviz y GTK.

De la web del autor:

xdot.py is an interactive viewer for graphs written in Graphviz’s dot language.

It uses internally the graphviz’s xdot output format as an intermediate format, and PyGTK and Cairo for rendering.
xdot.py can be used either as a standalone application from command line, or as a library embedded in your python application.

Features

  • Since it doesn’t use bitmaps it is fast and has a small memory footprint.
  • Arbitrary zoom.
  • Keyboard/mouse navigation.
  • Supports events on the nodes with URLs.
  • Animated jumping between nodes.
  • Highlights node/edge under mouse.

Este código ilustra como usar el widget en una aplicación. En la mía, genero dinámicamente el código dot según los nodos (recursos) que haya eligido el usuario. En los adjuntos puedes encontrar otro ejemplo mezclando rdflib y xdot:

Read the rest of this entry »

Tags: , , , , , , , , , , , , , , , , , , , , , ,


1 Comment »


~~ · ~~


Question about UTF-8

Posted on 18/08/2010, 15:56, by Tomás Vírseda, under Python.

Sometimes, I’ve noticed that my application doesn’t deal very well with UTF-8 input/output. UTF-8 is mandatory but it’s a headache when you have to spend your time guessing what is wrong and how display the right characteres. I’ve found this function to force encode any text into UTF-8.

keydict = {
    ‘zwnj’: ”, ‘aring’: ‘\xc3\xa5′, ‘gt’: ‘>’, ‘yen’: ‘\xc2\xa5′,
    ‘ograve’: ‘\xc3\xb2′, ‘Chi’: ‘\xce\xa7′, ‘delta’: ‘\xce\xb4′,
    ‘rang’: ‘\xe3\x80\x89′, ‘sup’: ‘\xe2\x8a\x83′,
    ‘trade’: ‘\xe2\x84\xa2′, ‘ge’: ‘\xe2\x89\xa5′, ‘xi’: ‘\xce\xbe’,
    ‘upsih’: ‘\xcf\x92′, ‘nbsp’: ”, ‘Atilde’: ‘\xc3\x83′,
    ‘radic’: ‘\xe2\x88\x9a’, ‘otimes’: ‘\xe2\x8a\x97′,
    ‘aelig’: ‘\xc3\xa6′, ‘oelig’: ‘\xc5\x93′, ‘equiv’: ‘\xe2\x89\xa1′,
    ‘ni’: ‘\xe2\x88\x8b’, ‘le’: ‘\xe2\x89\xa4′, ‘auml’: ‘\xc3\xa4′,
    ‘cup’: ‘\xe2\x88\xaa’, ‘Epsilon’: ‘\xce\x95′, ‘otilde’: ‘\xc3\xb5′,
    ‘lt’: ‘< ‘, ‘Icirc’: ‘\xc3\x8e’, ‘shy’: ”, ‘Eacute’: ‘\xc3\x89′,
    ‘ndash’: ‘\xe2\x80\x93′, ‘yacute’: ‘\xc3\xbd’,
    ‘Prime’: ‘\xe2\x80\xb3′, ‘prime’: ‘\xe2\x80\xb2′, ‘psi’: ‘\xcf\x88′,
    ‘Kappa’: ‘\xce\x9a’, ‘rsaquo’: ‘\xe2\x80\xba’, ‘Tau’: ‘\xce\xa4′,
    ‘alefsym’: ‘\xe2\x84\xb5′, ‘ocirc’: ‘\xc3\xb4′, ‘lrm’: ”,
    ‘zwj’: ”, ‘cedil’: ‘\xc2\xb8′, ‘Ecirc’: ‘\xc3\x8a’,
    ‘not’: ‘\xc2\xac’, ‘Dagger’: ‘\xe2\x80\xa1′, ‘AElig’: ‘\xc3\x86′,
    ‘oslash’: ‘\xc3\xb8′, ‘acute’: ‘\xc2\xb4′, ‘lceil’: ‘\xe2\x8c\x88′,
    ‘iquest’: ‘\xc2\xbf’, ‘uacute’: ‘\xc3\xba’, ‘laquo’: ‘\xc2\xab’,
    ‘dArr’: ‘\xe2\x87\x93′, ‘rdquo’: ‘\xe2\x80\x9d’,
    ‘Ntilde’: ‘\xc3\x91′, ‘Igrave’: ‘\xc3\x8c’, ‘nu’: ‘\xce\xbd’,
    ‘lsquo’: ‘\xe2\x80\x98′, ‘lsaquo’: ‘\xe2\x80\xb9′,
    ‘sube’: ‘\xe2\x8a\x86′, ‘rarr’: ‘\xe2\x86\x92′,
    ‘sdot’: ‘\xe2\x8b\x85′, ‘supe’: ‘\xe2\x8a\x87′, ‘Yacute’: ‘\xc3\x9d’,
    ‘lfloor’: ‘\xe2\x8c\x8a’, ‘lArr’: ‘\xe2\x87\x90′, ‘Auml’: ‘\xc3\x84′,
    ‘asymp’: ‘\xe2\x89\x88′, ‘Otilde’: ‘\xc3\x95′, ‘szlig’: ‘\xc3\x9f’,
    ‘clubs’: ‘\xe2\x99\xa3′, ‘agrave’: ‘\xc3\xa0′, ‘Ocirc’: ‘\xc3\x94′,
    ‘Theta’: ‘\xce\x98′, ‘Pi’: ‘\xce\xa0′, ‘harr’: ‘\xe2\x86\x94′,
    ‘Scaron’: ‘\xc5\xa0′, ‘frac14′: ‘\xc2\xbc’, ‘egrave’: ‘\xc3\xa8′,
    ‘sub’: ‘\xe2\x8a\x82′, ‘iexcl’: ‘\xc2\xa1′, ‘frac12′: ‘\xc2\xbd’,
    ‘ordf’: ‘\xc2\xaa’, ‘rlm’: ”, ‘prop’: ‘\xe2\x88\x9d’,
    ‘circ’: ‘\xcb\x86′, ‘ntilde’: ‘\xc3\xb1′, ‘apos’: "’",
    ‘atilde’: ‘\xc3\xa3′, ‘THORN’: ‘\xc3\x9e’, ‘theta’: ‘\xce\xb8′,
    ‘prod’: ‘\xe2\x88\x8f’, ‘nsub’: ‘\xe2\x8a\x84′,
    ‘hArr’: ‘\xe2\x87\x94′, ‘rArr’: ‘\xe2\x87\x92′, ‘Oslash’: ‘\xc3\x98′,
    ‘omicron’: ‘\xce\xbf’, ‘infin’: ‘\xe2\x88\x9e’, ‘yuml’: ‘\xc3\xbf’,
    ‘Mu’: ‘\xce\x9c’, ‘Psi’: ‘\xce\xa8′, ‘thinsp’: ‘\xe2\x80\x89′,
    ‘ecirc’: ‘\xc3\xaa’, ‘bdquo’: ‘\xe2\x80\x9e’, ‘Sigma’: ‘\xce\xa3′,
    ‘kappa’: ‘\xce\xba’, ‘Aring’: ‘\xc3\x85′, ’tilde’: ‘\xcb\x9c’,
    ‘emsp’: ‘\xe2\x80\x83′, ‘mdash’: ‘\xe2\x80\x94′,
    ‘uarr’: ‘\xe2\x86\x91′, ‘permil’: ‘\xe2\x80\xb0′, ‘tau’: ‘\xcf\x84′,
    ‘Ugrave’: ‘\xc3\x99′, ‘fnof’: ‘\xc6\x92′, ‘Agrave’: ‘\xc3\x80′,
    ‘sup1′: ‘\xc2\xb9′, ‘forall’: ‘\xe2\x88\x80′, ‘eth’: ‘\xc3\xb0′,
    ‘rceil’: ‘\xe2\x8c\x89′, ‘iuml’: ‘\xc3\xaf’, ‘gamma’: ‘\xce\xb3′,
    ‘lambda’: ‘\xce\xbb’, ‘reg’: ‘\xc2\xae’, ‘Egrave’: ‘\xc3\x88′,
    ‘sup3′: ‘\xc2\xb3′, ‘dagger’: ‘\xe2\x80\xa0′, ‘divide’: ‘\xc3\xb7′,
    ‘Ouml’: ‘\xc3\x96′, ‘image’: ‘\xe2\x84\x91′, ‘hellip’: ‘\xe2\x80\xa6′,
    ‘igrave’: ‘\xc3\xac’, ‘Yuml’: ‘\xc5\xb8′, ‘Oacute’: ‘\xc3\x93′,
    ‘pound’: ‘\xc2\xa3′, ‘eacute’: ‘\xc3\xa9′, ‘frasl’: ‘\xe2\x81\x84′,
    ‘ETH’: ‘\xc3\x90′, ‘lowast’: ‘\xe2\x88\x97′, ‘Nu’: ‘\xce\x9d’,
    ‘plusmn’: ‘\xc2\xb1′, ‘chi’: ‘\xcf\x87′, ‘sup2′: ‘\xc2\xb2′,
    ‘frac34′: ‘\xc2\xbe’, ‘Aacute’: ‘\xc3\x81′, ‘cent’: ‘\xc2\xa2′,
    ‘oline’: ‘\xe2\x80\xbe’, ‘Beta’: ‘\xce\x92′, ‘perp’: ‘\xe2\x8a\xa5′,
    ‘Delta’: ‘\xce\x94′, ‘loz’: ‘\xe2\x97\x8a’, ‘pi’: ‘\xcf\x80′,
    ‘iota’: ‘\xce\xb9′, ‘empty’: ‘\xe2\x88\x85′, ‘euml’: ‘\xc3\xab’,
    ‘brvbar’: ‘\xc2\xa6′, ‘iacute’: ‘\xc3\xad’, ‘para’: ‘\xc2\xb6′,
    ‘ordm’: ‘\xc2\xba’, ‘epsilon’: ‘\xce\xb5′, ‘uuml’: ‘\xc3\xbc’,
    ‘OElig’: ‘\xc5\x92′, ‘there4′: ‘\xe2\x88\xb4′,
    ‘part’: ‘\xe2\x88\x82′, ‘icirc’: ‘\xc3\xae’, ‘bull’: ‘\xe2\x80\xa2′,
    ‘upsilon’: ‘\xcf\x85′, ‘copy’: ‘\xc2\xa9′, ‘Iuml’: ‘\xc3\x8f’,
    ‘Lambda’: ‘\xce\x9b’, ‘Xi’: ‘\xce\x9e’, ‘ensp’: ‘\xe2\x80\x82′,
    ‘ccedil’: ‘\xc3\xa7′, ‘Ucirc’: ‘\xc3\x9b’, ‘cap’: ‘\xe2\x88\xa9′,
    ‘Upsilon’: ‘\xce\xa5′, ‘mu’: ‘\xce\xbc’, ‘sigmaf’: ‘\xcf\x82′,
    ‘scaron’: ‘\xc5\xa1′, ‘nabla’: ‘\xe2\x88\x87′,
    ‘isin’: ‘\xe2\x88\x88′, ‘Zeta’: ‘\xce\x96′, ‘minus’: ‘\xe2\x88\x92′,
    ‘deg’: ‘\xc2\xb0′, ‘and’: ‘\xe2\x88\xa7′, ‘real’: ‘\xe2\x84\x9c’,
    ‘ang’: ‘\xe2\x88\xa0′, ‘curren’: ‘\xc2\xa4′, ‘int’: ‘\xe2\x88\xab’,
    ‘ucirc’: ‘\xc3\xbb’, ‘rfloor’: ‘\xe2\x8c\x8b’, ‘crarr’: ‘\xe2\x86\xb5′,
    ‘ugrave’: ‘\xc3\xb9′, ‘notin’: ‘\xe2\x88\x89′, ‘exist’: ‘\xe2\x88\x83′,
    ‘cong’: ‘\xe2\x89\x85′, ‘Uuml’: ‘\xc3\x9c’, ‘oplus’: ‘\xe2\x8a\x95′,
    ‘times’: ‘\xc3\x97′, ‘Acirc’: ‘\xc3\x82′, ‘piv’: ‘\xcf\x96′,
    ‘Euml’: ‘\xc3\x8b’, ‘Phi’: ‘\xce\xa6′, ‘raquo’: ‘ \xc2\xbb’,
    ‘Iacute’: ‘\xc3\x8d’, ‘quot’: ”, ‘Uacute’: ‘\xc3\x9a’,
    ‘Omicron’: ‘\xce\x9f’, ‘ne’: ‘\xe2\x89\xa0′, ‘Iota’: ‘\xce\x99′,
    ‘eta’: ‘\xce\xb7′, ‘sbquo’: ‘\xe2\x80\x9a’, ‘Rho’: ‘\xce\xa1′,
    ‘darr’: ‘\xe2\x86\x93′, ‘Alpha’: ‘\xce\x91′, ‘zeta’: ‘\xce\xb6′,
    ‘Omega’: ‘\xce\xa9′, ‘acirc’: ‘\xc3\xa2′, ‘sim’: ‘\xe2\x88\xbc’,
    ‘phi’: ‘\xcf\x86′, ‘diams’: ‘\xe2\x99\xa6′, ‘macr’: ‘\xc2\xaf’,
    ‘larr’: ‘\xe2\x86\x90′, ‘Ccedil’: ‘\xc3\x87′, ‘aacute’: ‘\xc3\xa1′,
    ‘uArr’: ‘\xe2\x87\x91′, ‘beta’: ‘\xce\xb2′, ‘Eta’: ‘\xce\x97′,
    ‘weierp’: ‘\xe2\x84\x98′, ‘rho’: ‘\xcf\x81′, ‘micro’: ‘\xc2\xb5′,
    ‘alpha’: ‘\xce\xb1′, ‘omega’: ‘\xcf\x89′, ‘middot’: ‘\xc2\xb7′,
    ‘Gamma’: ‘\xce\x93′, ‘euro’: ‘\xe2\x82\xac’, ‘lang’: ‘\xe3\x80\x88′,
    ‘spades’: ‘\xe2\x99\xa0′, ‘amp’: ‘and’, ‘rsquo’: ‘\xe2\x80\x99′,
    ‘uml’: ‘\xc2\xa8′, ‘thorn’: ‘\xc3\xbe’, ‘ouml’: ‘\xc3\xb6′,
    ‘thetasym’: ‘\xcf\x91′, ‘or’: ‘\xe2\x88\xa8′, ‘Ograve’: ‘\xc3\x92′,
    ‘sect’: ‘\xc2\xa7′, ‘ldquo’: ‘\xe2\x80\x9c’,
    ‘hearts’: ‘\xe2\x99\xa5′, ‘sigma’: ‘\xcf\x83′,‘sum’: ‘\xe2\x88\x91′,
    ‘oacute’: ‘\xc3\xb3′
    }

def decode_unicode_references(data):
    try:
        text = data
        pos1 = text.find(‘&’)
        pos2 = text.find(‘;’)
        if (((pos1 != -1) or (pos2 != -1)) and (pos2 – pos1 < 15)):
            entity = text[pos1+1: pos2]
            a = text[pos1:pos2+1]
            return text.replace(a, keydict[entity])
        else:
            return data
    except:
        return data

def str2utf8(data):
    data = decode_unicode_references(data)
    guess_list=[‘utf-8′,‘iso8859-1′,‘iso8859-2′, \
                        ‘iso8859-15′,‘ascii’]
    encoding = ‘iso8859-1′
    text = None
    string = None
    for best_enc in guess_list:
        try:
            encoding = best_enc
            text = data.decode(encoding).encode(‘utf-8′)
            break
        except Exception, error:
            #print "ERROR:", error
            pass

    return text

How do you deal with UTF-8, python and gtk? Am I doing right? Do you know a better way?

Tags: , , , , , , , , , , , , , , , , ,


No Comments »


~~ · ~~