Python Gui Programming With: Pyside

Python GUI progr programming amming with PySide Speaker: BigLittle Date: 2013/03/04

CLI vs. GUI Interface) ace) CLI (Command Line Interf •

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GUI (Graphical User Interface)

Take less resources.

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User have much more control of their sys system. tem.

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Only need to execute few line to perform a task.

Easier for user to view and control your application. Ability of multitasking.

About Python + GUI •

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Some GUI library for Python: •

Tkinter

- Python's standard GUI package. (Tcl/Tk)

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wxPython - A Python extension module that wraps wxWidgets  library.

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PyQt4

- A Python binding of the cross-platform GUI toolkit Qt.

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PySide

- A Python binding of the cross-platform GUI toolkit Qt.

Qt & wxWidgets are both well known C++ GUI library: •

They are free and open source.

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They are cross-platform and support Unicode.

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They have full documentation and community support.

Why Qt / PySide? •

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Pros: •

It’s NOT MFC style.

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Easy to build up by QtDesigner or text coding.

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Intuitive SIGNAL / SLOT mechanism.

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Supports I18N. (Internationalization)

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LGPL. (GNU Lesser General Public License)

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The API is more Pythonic.

Cons: •

Qt is not written in standard C++ library.

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Application size is big.

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blabla……

I don’t care, and you?

Before Starting… •

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Install Python (What?!) •

http://www.python.org/download

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User should note the compatibility between version 2.7.x and 3.x.

Install Qt •

http://qt-project.org/downloads

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The latest version is 5.0. (It’s too new for me... =.=)

Install PySide •

http://qt-project.org/wiki/PySideDownloads

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Current version is 1.1.2, but most references on web is for 1.0.7.

A Simple Program •

test.py

object oriented programming styles

Just so easy!

A Simple Program (cont’d) •

test.py Import PySide module here.

A Simple Program (cont’d) •

test.py

Inherit class “QMainWindow”

set it’s title then show itself.

A Simple Program (cont’d) •

test.py

Contains the main event loop. Create MyWindow instance

A Simple Program (cont’d) •

test.py

Actually, the easiest way may be:

app = QApplication(sys.argv) main = QMainWindow() main.setWindowTitle(“First GUI”) main.show() sys.exit(app.exec_())

Trigger when execute test.py.

Where Is Other Stuff? •

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Just like a HD, you must format it then you can put in your data. •

HD

  Current

Window

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Format

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QLayout

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Data

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QWidget

QLayout and QWidget are the most basic classes that make up your GUI.

QMainWindow is a subclass of QWidget. Right figure shows the default configuration.

QLayout •

In fact, you don’t need to start from QLayout itself. There are many pre-designed layout. Use them directly should be enough.

QHBoxLayout

QGridLayout QVBoxLayout

QFormLayout

QWidget •

Example

Think: What’s the layout setting in the QGroupBox?

Let’s Put Something On It 

How To Activate It? •

Now you have a “skin” of your application. Let’s make it activated. For example, push “Big” button then type “Bigger” on the editor. trigger

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response

In Qt, trigger & response are called SIGNAL & SLOT

SIGNAL / SLOT •

self.btn1.clicked.connect(self.typebig) •

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The advantage of SIGNAL / SLOT is the caller does not have to know anything about the receiver and vice versa.

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Any function could be a SLOT.

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One can connect several SLOT to a SIGNAL and vice versa.

A common usage: Real-time check for input contents

Exercise… •

Try to modify the simple program to MD5 Encrypter.

Exercise… (cont’d) •

You need import hashlib first

Use Advanced Module •

Matplotlib - A Python plotting library. (Based on PySide!)

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SciPy

- An open source library of scientific tools for Python.

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VTK

- Visual Tool Kit (TVTK, Mayavi)

Much Better Than Excel… •

Source code: http://matplotlib.org/examples/pylab_examples/demo_agg_filter.html

Something To Be Continued •

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Decorations: •

Take advantages of groups, tabs, tooltips, …, etc.

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Add some icons, sounds or visual effects.

Maintains: •

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CurveExpert (PyInstaller)

Debug, debug and debug.

Packing/Release: •

PyInstaller - Cross platform

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cx_Freeze - Cross platform

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py2exe

- Window only BitTorrent (py2exe)

Create Your Own GUI App! •

Model-View-Controller

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Automation Tool

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Distributed Programming

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Database Management

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Multimedia

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CAD Software

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Embedded System

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Web Application

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Games

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Summary •

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GUI programming could help you interactively control the application and report visualized final data. Every programmer should familiar with its basic concept. Programming in PySide = Programming in OOP. All components in library can be easily adapted and modified. Try to use them as much as possible. There are many “splendid” functions like graphics, animation, drag & drop…, etc. for GUI programming. You can improve the user experience by these, but remember to pay more attention on the performance of your application.

References •

http://zh.wikipedia.org/wiki/Qt

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http://qt-project.org/wiki/PySide

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http://matplotlib.org

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http://www.scipy.org

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http://www.vtk.org

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http://www.pyinstaller.org

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http://cx-freeze.sourceforge.net

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http://www.py2exe.org

Thanks for your attention.