Programming on dennogumi.org

PyKDE4: new style signals and slots

Sat, 06 Mar 2010 08:04:48 +0000

Those who use PyQt and PyKDE4 are certainly familiar with the syntax used to connect signals and slots:

[python] from PyQt4 import QtCore from PyQt4 import QtGui from PyKDE4 import kdeui

class MyGUI(QtGui.QWidget):

def __init__(self, parent=None):
    super(MyGUI, self).__init__(parent)
    self.pushbutton = kdeui.KPushButton()
    self.pushbutton.setText("Push me!")
    
    QObject.connect(self.pushbutton, QtCore.SIGNAL("clicked()"), 
                           self.button_pushed)

def button_pushed(self):
    print "Button clicked"

[/python]

The main advantage of this syntax is that it’s very close to the C++ equivalent, and so you can translate easily from C++ to Python. Unfortunately the advantages of this syntax end here. The disadvantages, at least from a Python coding perspective, outweigh the advantages:

DataMatrix page up

Sun, 12 Oct 2008 20:14:14 +0000

Ok, ok… my definition of “tomorrow” is not like what most people use, apparently. Although I took quite a while, now there is a static page on DataMatrix. There you will find a summary of wht I wrote in my other blog posts regarding this module. Of course, it will be kept up-to-date should I release a new version.

Aside that, I put a contact form on this blog. It may be useful for reports that aren’t directly related to the posts.

DataMatrix 0.5

Fri, 19 Sep 2008 19:54:58 +0000

At last, since it’s been like ages, I decided to put out a new version of DataMatrix. For those who haven’t seen my previous post, DataMatrix is a Pythonic implementation of R’s data.frame. It enables you to manipulate a text file by columns or rows, to your liking, using a dictionary-like syntax.

In this new version there have been a few improvements and correction to a couple bugs (for example saveMatrix did not really save) and the start (only a stub at the moment) of an append function to add more columns (I’ll also think about a function to add rows).

data.frames in Python - DataMatrix

Sun, 29 Jun 2008 08:13:55 +0000

For a long time I have tried to handle text files in Python in the same way that R’s data.frame does - that is, direct access to columns and rows of a loaded text file. As I don’t like R at all, I struggled to find a Pythonic equivalent, and since I found none, I decided to eat my own food and write an implementation, which is what you’ll find below.

QSql vs DB-API?

Fri, 28 Dec 2007 12:58:40 +0000

I’ve recently begun trying to create GUIs for my Python applications with PyQt, and I can say I’m absolutely loving the toolkit, relatively easy to use and featureful. As I’m trying to create a GUI for some module I wrote that deals with databases (using MySQLdb), I also learnt that Qt has a series of classes for dealing with databases, mainly QSql.

My question, directed to whoever has experience with QSql and the Python DB-API, is: what are the advantages of one approach to the other? I’m leaning towards DB-API because like that I can create modules which work also in command line applications.