Getting Interactive With PyQt

One of the cooler features with PyQt (IMHO) is the possibility to write Qt code interactively. It isn't actually something new and I'm sure it's been there for a while but some of you might not be aware of it. I find it very useful when I want to learn new things in Qt, so without further ado, here's a short introduction on using it.

Start an interactive python session by executing python in a shell:

$> python
Python 2.6.6 (r266:84292, Sep 15 2010, 16:22:56) 
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>

Let's create a simle top-level window (I wont add the '>>>' in case you would like to copy/paste the code):

from PyQt4.QtCore import *
from PyQt4.QtGui import *
app = QApplication([])
window = QWidget()
window.resize(400, 300)
window.show()

Now you should have a window similar to the screen shot below:

Ok, let's create a push button:

button = QPushButton("Click Me!", window)

Hmm, no button shows up... Why? Well, that's because we need to make it visible after we have added it to the window:

button.show()

Ahh, sweet! We have added the button to the window interactively:

Let's put the button at the center of the window by using a layout manager:

layout = QHBoxLayout(window)
layout.addWidget(button)

And finally, let's see how 'layout.addStretch()' affects the layout:

layout.addStretch()

You can easily add a slot to the button's clicked signal:

def mySlot():
    print "Button Clicked"
button.clicked.connect(mySlot)

As you can see, it's an easy way to try out thing in Qt.

Thanks for reading!