[Tutorial] Python GUI Programming Part I

[Acid_Snake]

There are many GUI toolkits available for python: pygtk, pyqt, wxpython, etc. But the default toolkit used is Tkinter. Tkinter is a wrapper for the Tcl toolkit, it doesn't have much widgets and features but it's simplicity makes it a perfect candidate for a quick and simple work.


Importing Tkinter:
The method for importing Tkinter varies mostly due to the operation system case sensitivity, but it's mostly this:

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import Tkinter

or this:

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import tkinter

Most people also prefer to use the variable tk:

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import Tkinter as tk

The main window:
Every GUI has a main window, that is of course the window where all widgets will be placed. In Tkinter this as simple as:

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main_window = Tkinter.Tk()

and then we start the window's mainloop:

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main_window.mainloop()

You can also name your main window, this name will be displayed as the app name:

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main_window = Tkinter.Tk(className="My first Tkinter program")

Widgets:
Having a main window is important, but it doesn't serve any purpose to the end user, that is why we need to use widgets depending on what the program needs. There are many widgets available in Tkinter and they use the same or similar ways to be displayed. We will investigate most (if not all) widgets in part II, now you need to learn the basics.


A simple app:
Every programming language starts with a simple app, usually Hello World so that's what I'm going to show here.
For the hello world we need to show text, and there are two methods in Tkinter to show text: the label widget and the text widget.
The label widget, just like it's name implies, is used to name different parts of the GUI in single line, while the text widget is used for multi line text. This difference has become less of a problem since the label widget is capable of multi line text using the \n character or the triple quotation, this and the fact that you can display images with the label widget has made the text widget rather unnecessary. Long story short: we will be using the label widget for the hello world example.
First we need to make the main window:

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gui = Tkinter.Tk(className="Hello GUI")

Now we crate the label widget with the text we want to show:

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label = Tkinter.Label(gui, text="Hello World")

As you can see the first argument to pass at any widget is where they will be placed, normally is a window, but it can also be a frame (more on that later).
The next thing we need is to pack the widget:

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label.pack()

Don't forget to pack your widgets, otherwise the won't show up.
And of course we create the mainloop:

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gui.mainloop()

The entire code would be:

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#! /usr/bin/env python
import Tkinter
gui = Tkinter.Tk(className="Hello GUI")
label = Tkinter.Label(gui, text="Hello World")
label.pack()
gui.mainloop()

And the result? this:

Hello_Gui.png (4.88 KiB) Viewed 1421 times

More widgets later...
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[waratte]

Wow that's simple. :o

/me might consider trying to learn python again

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[qwikrazor87]

Back to school. I feel like a noob again.