First Steps with Python + Qt # 1

This tutorial is focused on teaching the use of the QT framework using Python as a programming language, for this we can use both PySide and PyQt, but in this tutorial we will use PySide because the author of this tutorial likes the LGPL PySide license better. than the GPL or PyQt Commercial.

First ... What is Python?

According to Wikipedia:

"Python is a very high-level interpreted programming language whose philosophy emphasizes very clean syntax and favors readable code."

Python is a multipadradigm programming language, so it supports different python programming paradigms, for example it supports: Object Oriented Programming (OOP), Imperative Programming (Structured) and to a lesser extent Functional programming.

Only that?

No, it is also a dynamic typing language, which means that python allows us to assign different types of values ​​to the same variable during the execution of the program, some see it as an advantage, others as a disadvantage, see for yourself.

In addition to what has already been mentioned, Python allows us (like many others), programming both in the web environment and in the web desktop, it is also cross-platform, currently it supports Gnu / Linux, Windows, Mac osx, Android (If you need to mention them for your modification).

What is QT?

QT is a multiplatform framework, originally developed by Nokia, to later be sold to Digia, which is used for application development, it is written in C ++, but can be used in other languages ​​through Bindings (in our case PySide or PyQt )

Differences between PySide and PyQt

Mainly

• License, PySide is licensed under the terms of the LGPL and PyQT is under the terms of the GPL or under a commercial license, so we would need to pay in case of creating a closed application.
• PySide is created by Nokia, and PyQt by RiverBank.
• PySide saves us the trouble of using STR every time we use the QString of each of the QT objects.

We can detail the complete changes Here.

Preparation:

We install Qt:

If we have a distro with Kde we should already have what we need, if not:

sudo apt-get install qt4-dev-tools

We install PySide:

sudo apt-get install pyside pyside-tools

Our First Python + QT Application

We go to our favorite text editor, I recommend that you install sublime-text2, but you can use the one you prefer, and we type the following code and save it with the name that we want always ending with the extension ".py", I will I'll save as app1.py:

See Code

We run it from the console like this:

python app1.py

This window should appear

What? Only That, because if you only had a console before, what are you complaining about? What did you expect, an Erp? Come on man, something starts.

Now let's explain the code:

from PySide.QtGui import *

from sys import exit, argv

Here we import the necessary modules for PySide execution.

app = QApplication(argv)

We create the Qapplication instance with the name app.

window = Qwidget()

We create the QWidget () instance.

window.setWindowTitle("Primera App PySide")

We execute the setWindowTitle method, which receives a String as a parameter to "set" the title of our Qwidget.

window.show()

We show our window

exit(app.exec_())

finally we execute the infinite cycle of execution of our QApplication ().

Thank you

Thank you for those who have followed me here and have been useful. For the next tutorial I will explain how to design our windows with QT Designer and import them into our projects.

Additionally, I add the link to the forum desde linux where I have a small theme with a small library of python tutorials and guides, containing different terms including:

Basic Python Tutorials

wxPython

PyQt and PySide

Django

web2py

Scientific programming in python.

And many more.

LINK TO THE FORUM

I hope they serve you, I say goodbye, as always a pleasure to belong to this wonderful community.