DOCSLIB.ORG

Lecture 3: Programs and Testing CS-A1123 Basics in Programming Y2 Winter and Spring 2020 Timo Kiravuo, D.Sc

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Lecture 3: Programs and Testing CS-A1123 Basics in Programming Y2 Winter and Spring 2020 Timo Kiravuo, D.Sc Lecture 3: Programs and Testing CS-A1123 Basics in Programming Y2 Winter and Spring 2020 Timo Kiravuo, D.Sc. Objects and User Interfaces Data Structures in Objects • Programs manipulate data and they need to store it somewhere • During processing: data structures in memory • In general: the file system (exercise 4) • A database is a specific service that uses the file system • Data structures need to be designed • This will likely become apparent with the exercises • The Object Oriented model is not just an implementation feature • It is a key technology for modeling and designing software Testing • After implementation testing is mandatory • First by thinking things through • Walk through your design • Will be a bit challenging along this course, as we are still learning the basics, too • Once there is written code, various tools can be used • Testing can be a programming methodology, too • Test Driven Development (TDD) • Figure out what the software has to do and write tests first • Then write the program to pass the tests PyQt User Interface Library • PyQt is a software library for providing graphical features • A large feature set and fast execution • Works on different platforms (Windows, Linux, MacOS) • Contains about 600 classes and 6000 functions and methods • Implements the QT graphics toolkit for Python • Others graphics libraries exist for Python, too • PySide, PyGTK, wxPython, Tkinter • Matches graphical features on the screen (widgets) to objects in software Using PyQT the Procedural Way • Procedural programming (from Y1) uses subprograms • Subprograms typically operate on data structures in the program's memory • This creates a window on the display using PyQt5 import sys from PyQt5.QtWidgets import QWidget, QPushButton, QApplication def Example(): app = QApplication(sys.argv) w = QWidget() b = QPushButton('Push', w) b.clicked.connect(w.close) w.show() sys.exit(app.exec_()) Doing the Same in Object Oriented Way • We create class that contains both data and functionality • This brief sample does not show how to use the class class Example(QWidget): def __init__(self): super().__init__() self.initUI() def initUI(self): self.__btn = QPushButton('Push', self) self.show() def activate_close(self): self.__btn.clicked.connect(self.close) self.show() Observations on the Comparison • We could make the procedural version more general by using arguments • Functionality is still defined by this one subprogram • Object oriented version could use more methods • But out object is already very capable • Type "help(Example)" to see this • Functionalities are bound to the object and come from parent classes • Other paradigms exist • Functional, rule based logic etc. • In general it is recommended to use one paradigm for one software project Errors and Testing Errors, Mistakes and Finding Them • Errors in software are often obvious • Once found, locating them can be very hard • Main problem is in specifying the actual task to be done • A perfect specification is easily as long as the software implementation • Most specifications are informal (natural language) • An implemented program can be considered to be the specification • Validating • Are we doing the right thing? • Is our specification right? • Verification • Is our implementation right, does it correspond to the specification? Static and Dynamic Testing and Analysis • Static methods look at the code without any particular input • Interpreters and compilers do this as part of their process • Produce warnings and errors • Defining data types is often useful for static analysis • Various tools are available for common languages for code analysis • Dynamic methods execute the software with input and check output • Repeatable tests with defined data • Random tests to catch errors not even expected by testers • Both methods are commonly used for testing as part of the production process Types of Testing • Typically there are different levels of testing during a project • Unit testing: verify the functionality of a particular function or class • Integration testing: combine multiple components and test their interoperation • Systems testing: testing the overall system, can include performance testing • Acceptance testing: Verifying that the product meets the specification • Regression testing: repeating already passed tests after changes to the software • Types of tests and their coverage depend on the project • Automation of testing is very important Testing as Part of Programming • Testing can be a separate process and also performed by the programmers themselves • Generally people are not very good at testing their own code, as they focus on its expected behavior • Testing is a separate discipline of software development and large projects usually have specific testing staff • Finding and fixing the actual mistake in code is left to the programmers Coverage of Tests • Coverage, how much of the created program is tested, is a central issue • Many ways to measure coverage • Function coverage: have all functions been called? • Branch coverage: have all branches been taken? • Clause coverage: has each condition been evaluated as both true and untrue • Path coverage: has every possible path the software can take been executed • Usually not possible to reach • Even complete coverage does not guarantee that there are no mistaks • Formally proving a program correct is not feasible in practice, due to the near infinite amount of branches a program's execution can take Unit Testing on this Course • A typical unit test consists of • Test code that calls the unit, usually brief • Written description of the test, e.g. which methods to call in order, such as: Add(0), Add(1), Delete(0) • Test input to be used • Possibly the program state before the test (which variables to be set etc.) • Expected output and program state after the test • Unit tests usually use a library of framework to take care of housekeeping matters • Runs the tests, records output, reports results • There is more to testing, this is sufficient for this course Basic Testing Features of Python Module unittest • Object oriented testing methodology • Designed to test classes • Module contains several classes • TestCase for defining individual tests • TestSuite to create the whole test package • TestRunner to perform the tests • Other useful tools are • unittest.mock to emulate functionality that does not exist • Module doctest picks test cases embedded in documentation in the module file An Unittest Sample import unittest class TestStringMethods(unittest.TestCase): def test_upper(self): self.assertEqual('foo'.upper(), 'FOO') def test_isupper(self): self.assertTrue('FOO'.isupper()) self.assertFalse('Foo'.isupper()) def test_split(self): s = 'hello world' self.assertEqual(s.split(),['hello','world']) # check s.split fails when not a string with self.assertRaises(TypeError): s.split(2) Notes on module unittest • Pay attention to setting up tests • Variables and other data structures • Unit tests may be executed in any order • Module unittest alphabetical by default • If your tests depend on the execution order, it is not unit testing any more... A Bit More about Computers and Programming Networked, distributed and embedded computing • Most computing devices are now networked • Internet the most common example • Networking creates distributed systems • The actual network is hidden by the overall system • Internet itself consists of millions of subnets that are not visible to its users • Embedded systems are computers in devices that do not look like computers • Car's brake systems, household appliances etc. • IoT, Internet of Things Terminal Devices, Servers and the Cloud • Different roles for different computing devices in the network • Based on use and location • E.g. video servers and mobile phones • Client-server model is currently a very common architecture • Client software in the terminal device • App in mobile phone, JavaScript in browser • Server in the cloud • The cloud is flexible networked computing resource, where data can be stored and software rapidly deployed as needed • This means that code will be executed in different environments • Hard to predict where your program will end up • Impacts on performance, security etc. Software Stacks and Packages • Systems consists usually of several software components • These are connected by interfaces • Inside the code these are usually just names • Note the Python import command • PyQt is actually written in C++, but this does not matter • Externally the whole is referred to as software stack • Software stack: all components surrounding the code being developed • Python's own software stack has many packages • The standard library implements only part of the full functionality • The number of various packages and their versions is very large • Package and version management is an important part of software development Virtual Environments • Common operating systems usually contain an installed software stack of their own • Browser, various libraries • Can easily create interference with the packages needed by particular software, such as our own Python development • Python supports virtual environments • venv and virtualenv • Limit the scope of a particular process and control which packages are available • Python also contains tools for package management • pip installer • pip can also install packages to the virtual environments • When using your computer for development virtual environments help avoiding clutter • It is easy to install too many packages with overlapping names Recommendation • Figure out how to use the Python "venv" on your own computer before continuing this course • Later exercises require installing some packages with "pip" and you might not want them on your computer after the course • Easy as, using subdirectory foo: python3 -m venv foo . foo/bin/activate pip3 some nice packages ... do stuff ... deactivate Exercises Exercise 3: Tested Code • Learn to test your code • Things are getting harder now, this will take more time • Read the assignment first and think, before starting • Two main tasks • Testing the function "weekdays" • Unit testing • Linked list • Meet the specification.
Load more

Recommended publications
  • Python Qt Tutorial Documentation Release 0.0
    Python Qt tutorial Documentation Release 0.0 Thomas P. Robitaille Jun 11, 2018 Contents 1 Installing 3 2 Part 1 - Hello, World! 5 3 Part 2 - Buttons and events 7 4 Part 3 - Laying out widgets 9 5 Part 4 - Dynamically updating widgets 13 i ii Python Qt tutorial Documentation, Release 0.0 This is a short tutorial on using Qt from Python. There are two main versions of Qt in use (Qt4 and Qt5) and several Python libraries to use Qt from Python (PyQt and PySide), but rather than picking one of these, this tutorial makes use of the QtPy package which provides a way to use whatever Python Qt package is available. This is not meant to be a completely exhaustive tutorial but just a place to start if you’ve never done Qt development before, and it will be expanded over time. Contents 1 Python Qt tutorial Documentation, Release 0.0 2 Contents CHAPTER 1 Installing 1.1 conda If you use conda to manage your Python environment (for example as part of Anaconda or Miniconda), you can easily install Qt, PyQt5, and QtPy (a common interface to all Python Qt bindings) using: conda install pyqt qtpy 1.2 pip If you don’t make use of conda, an easy way to install Qt, PyQt5, and QtPy is to do: pip install pyqt5 qtpy 3 Python Qt tutorial Documentation, Release 0.0 4 Chapter 1. Installing CHAPTER 2 Part 1 - Hello, World! To start off, we need to create a QApplication object, which represents the overall application: from qtpy.QtWidgets import QApplication app= QApplication([]) You will always need to ensure that a QApplication object exists, otherwise your Python script will terminate with an error if you try and use any other Qt objects.
    [Show full text]
  • Testing Pyside/Pyqt Code Using the Pytest Framework and Pytest-Qt
    Testing PySide/PyQt Code Using the pytest framework and pytest-qt Florian Bruhin “The Compiler” Bruhin Software 06. November 2019 Qt World Summit, Berlin About me • 2011: Started using Python • 2013: Started using PyQt and developing qutebrowser • 2015: Switched to pytest, ended up as a maintainer • 2017: qutebrowser v1.0.0, QtWebEngine by default • 2019: 40% employed, 60% open-source and freelancing (Bruhin Software) Giving trainings and talks at various conferences and companies! Relevant Python features Decorators registered_functions: List[Callable] = [] def register(f: Callable) -> Callable: registered_functions.append(f) return f @register def func() -> None: .... Relevant Python features Context Managers def write_file() -> None: with open("test.txt", "w") as f: f.write("Hello World") Defining your own: Object with special __enter__ and __exit__ methods. Relevant Python features Generators/yield def gen_values() -> Iterable[int] for i in range(4): yield i print(gen_values()) # <generator object gen_values at 0x...> print(list(gen_values())) # [0, 1, 2, 3] PyQt • Started in 1998 (!) by Riverbank Computing • GPL/commercial • Qt4 $ PyQt4 Qt5 $ PyQt5 PySide / Qt for Python • Started in 2009 by Nokia • Unmaintained for a long time • Since 2016: Officially maintained by the Qt Company again • LGPL/commercial • Qt4 $ PySide Qt5 $ PySide2 (Qt for Python) Qt and Python import sys from PySide2.QtWidgets import QApplication, QWidget, QPushButton if __name__ == "__main__": app = QApplication(sys.argv) window = QWidget() button = QPushButton("Don't
    [Show full text]
  • Asyncprotect T1 Extunderscore Gui Documentation
    async_gui Documentation Release 0.1.1 Roman Haritonov Aug 21, 2017 Contents 1 Usage 1 1.1 Installation................................................1 1.2 First steps.................................................1 1.3 Tasks in threads.............................................2 1.4 Tasks in processes............................................3 1.5 Tasks in greenlets.............................................3 1.6 Returning result.............................................3 2 Supported GUI toolkits 5 3 API 7 3.1 engine..................................................7 3.2 tasks...................................................8 3.3 gevent_tasks...............................................9 4 Indices and tables 11 Python Module Index 13 i ii CHAPTER 1 Usage Installation Install with pip or easy_install: $ pip install --upgrade async_gui or download latest version from GitHub: $ git clone https://github.com/reclosedev/async_gui.git $ cd async_gui $ python setup.py install To run tests: $ python setup.py test First steps First create Engine instance corresponding to your GUI toolkit (see Supported GUI toolkits): from async_gui.tasks import Task from async_gui.toolkits.pyqt import PyQtEngine engine= PyQtEngine() It contains decorator @engine.async which allows you to write asynchronous code in serial way without callbacks. Example button click handler: @engine.async def on_button_click(self, *args): self.status_label.setText("Downloading image...") 1 async_gui Documentation, Release 0.1.1 # Run single task in separate thread
    [Show full text]
  • CIS192 Python Programming Graphical User Interfaces
    CIS192 Python Programming Graphical User Interfaces Robert Rand University of Pennsylvania November 19, 2015 Robert Rand (University of Pennsylvania) CIS 192 November 19, 2015 1 / 20 Outline 1 Graphical User Interface Tkinter Other Graphics Modules 2 Text User Interface curses Other Text Interface Modules Robert Rand (University of Pennsylvania) CIS 192 November 19, 2015 2 / 20 Tkinter The module Tkinter is a wrapper of the graphics library Tcl/Tk Why choose Tkinter over other graphics modules I It’s bundled with Python so you don’t need to install anything I It’s fast I Guido van Rossum helped write the Python interface The docs for Tkinter aren’t that good I The docs for Tk/Tcl are much better I Tk/Tcl functions translate well to Tkinter I It’s helpful to learn the basic syntax of Tk/Tcl Tk/Tcl syntax ! Python: I class .var_name -key1 val1 -key2 val2 ! var_name = class(key1=val1, key2=val2) I .var_name method -key val ! var_name.method(key=val) Robert Rand (University of Pennsylvania) CIS 192 November 19, 2015 3 / 20 Bare Bones Tkinter from Tkinter import Frame class SomeApp(Frame): def __init__(self, master=None): tk.Frame.__init__(self, master) def main(): root = tk.Tk() app = SomeApp(master=root) app.mainloop() if __name__ ==’__main__’: main() Robert Rand (University of Pennsylvania) CIS 192 November 19, 2015 4 / 20 Images By default, Tkinter only supports bitmap, gif, and ppm/pgm images More images are supported with Pillow Pillow is a fork of Python Imaging Library pip install pillow from PIL import Image, ImageTk Create a PIL
    [Show full text]
  • Multiplatformní GUI Toolkity GTK+ a Qt
    Multiplatformní GUI toolkity GTK+ a Qt Jan Outrata KATEDRA INFORMATIKY UNIVERZITA PALACKÉHO V OLOMOUCI GUI toolkit (widget toolkit) (1) = programová knihovna (nebo kolekce knihoven) implementující prvky GUI = widgety (tlačítka, seznamy, menu, posuvník, bary, dialog, okno atd.) a umožňující tvorbu GUI (grafického uživatelského rozhraní) aplikace vlastní jednotný nebo nativní (pro platformu/systém) vzhled widgetů, možnost stylování nízkoúrovňové (Xt a Xlib v X Windows System a libwayland ve Waylandu na unixových systémech, GDI Windows API, Quartz a Carbon v Apple Mac OS) a vysokoúrovňové (MFC, WTL, WPF a Windows Forms v MS Windows, Cocoa v Apple Mac OS X, Motif/Lesstif, Xaw a XForms na unixových systémech) multiplatformní = pro více platforem (MS Windows, GNU/Linux, Apple Mac OS X, mobilní) nebo platformově nezávislé (Java) – aplikace může být také (většinou) událostmi řízené programování (event-driven programming) – toolkit v hlavní smyčce zachytává události (uživatelské od myši nebo klávesnice, od časovače, systému, aplikace samotné atd.) a umožňuje implementaci vlastních obsluh (even handler, callback function), objektově orientované programování (objekty = widgety aj.) – nevyžaduje OO programovací jazyk! Jan Outrata (Univerzita Palackého v Olomouci) Multiplatformní GUI toolkity duben 2015 1 / 10 GUI toolkit (widget toolkit) (2) language binding = API (aplikační programové rozhraní) toolkitu v jiném prog. jazyce než původní API a toolkit samotný GUI designer/builder = WYSIWYG nástroj pro tvorbu GUI s využitím toolkitu, hierarchicky skládáním prvků, z uloženého XML pak generuje kód nebo GUI vytvoří za běhu aplikace nekomerční (GNU (L)GPL, MIT, open source) i komerční licence např. GTK+ (C), Qt (C++), wxWidgets (C++), FLTK (C++), CEGUI (C++), Swing/JFC (Java), SWT (Java), JavaFX (Java), Tcl/Tk (Tcl), XUL (XML) aj.
    [Show full text]
  • Writing Standalone Qt & Python Applications for Android
    Writing standalone Qt & Python applications for Android Martin Kolman Red Hat & Faculty of Informatics, Masaryk University http://www.modrana.org/om2013 [email protected] 1 Overview Writing Android applications with Python and Qt How it works The pydroid project Examples Acknowledgement 2 Writing Android applications with Python and Qt Lets put it all together ! So that: applications can be written entirely in Python Qt/QML can be used for the GUI the result is a standalone Google Play compatible APK package deployment is as easy as possible all binary components can be recompiled at will 3 Writing Android applications with Python and Qt Writing Android applications with Python and Qt Python has been available for Android for ages the Qt graphics library has been available for Android since early 2011 there have been some proof of concepts of Qt-Python bindings working on Android and even some proof of concepts of distributing Python + Qt applications 4 How it works How “normal” Android applications look like written in the Android Java running on the Dalvik VM can have a native backend written in C/C++ using the Android NDK application packages are distributed as files with the .apk extension there is no support for cross-package dependencies 5 How it works Necessitas - Qt for Android provides Qt libraries compiled for Android 2.2+ most of Qt functionality is supported, including OpenGL acceleration and Qt Quick handles automatic library downloads & updates through the Ministro service 6 How it works Python
    [Show full text]
  • Pyside Overview
    PySide overview Marc Poinot (ONERA/DSNA) Outline Quite short but practical overview ▶Qt ■ Toolkit overview ■ Model/View ▶PySide ■ pyQt4 vs PySide ■ Designer & Cython ■ Widget bindings ■ Class reuse PySide - Introduction ONERA/PySide-2/8 [email protected] Qt - Facts ▶Qt is cute ■ Cross platform application framework for GUI X Window System, Windows... ■ C++ kernel + many bindings Including Python ■ Release v5.3 05/2014 ■ License GPL+LGPL+Commercial Contact your own lawyer... ▶Components ■ Core: QtCore, QtGui... ■ Specialized: QtWebKit, QtSVG, QtSQL... ■ Tools : Creator, Designer... PySide - Introduction ONERA/PySide-3/8 [email protected] Qt - Example PySide - Introduction ONERA/PySide-4/8 [email protected] Python bindings ▶pyQt ■ The first to come Some services have hard coded import PyQt4 ■ GPL - Use only in free software ▶PySide ■ Some syntactic & behavior differences ■ LGPL - Use allowed in proprietary software PySide overview hereafter mixes Qt/PySide features PySide - Introduction ONERA/PySide-5/8 [email protected] PySide - Facts ▶Full Python binding ■ Qt classes as Python classes ■ Python types as parameter types ▶Release 1.2.2 04/2014 ▶Reference documentation http://pyside.github.io/docs/pyside/ ▶Production process ■ Uses many steps ■ Better with setup & source management PySide - Introduction ONERA/PySide-6/8 [email protected] PySide - Production process W class Ui_W class WB(QWidget,Ui_W) ☺ A.ui uic ui_A.pyx Designer B.py cython A.c A.so A.rc rcc Res_rc.py PySide - Introduction ONERA/PySide-7/8 [email protected]
    [Show full text]
  • Pyqt-Käyttöliittymäkirjasto Pyqt-Käyttöliittymäkirjasto
    PyQt-käyttöliittymäkirjasto PyQt-käyttöliittymäkirjasto • PyQt on laaja ja yleinen kirjasto – Tehokas grafiikka ja monipuoliset ominaisuudet – Toimii monilla eri alustoilla – PyQt5 pitää sisällään 620 luokkaa ja 6000 funktiota ja metodia • Muita vastaavia käyttöliittymäkirjastoja: – PySide, PyGTK, wxPython, Tkinter • Qt on käytettävissä monesta muustakin kielestä – PyQt on joukko sidontoja alla olevaan Qt-toteutukseen – PyQt on toteutettu joukkona Python moduuleita • Keskeinen käsite ovat käyttöliittymäkomponentit (widget) – Ne vastaavat usein suoraan ikkunaan ilmestyviä graafisia olioita 2 Esimerkki: proseduaalinen ohjelmointi • Proseduraalisessa ohjelmoinnissa luodaan aliohjelmia – Tyypillisesti muuttavat ohjelman tietorakenteiden tilaa • Oheinen luo ikkunan PyQt5:llä import sys from PyQt5.QtWidgets import QWidget, QPushButton, QApplication def Example(): app = QApplication(sys.argv) w = QWidget() b = QPushButton('Push', w) b.clicked.connect(w.close) w.show() sys.exit(app.exec_()) 3 Esimerkki: sama olio-ohjelmoinnilla • Olio-ohjelmoinnissa luomme luokan – Perustoiminnallisuus rakennetaan olioon, jota käytetään • Ohessa widget-olion kutsuminen yms. on jätetty pois class Example(QWidget): def __init__(self): super().__init__() self.initUI() def initUI(self): self.__btn = QPushButton('Push', self) self.show() self.activate_close() def activate_close(self): self.__btn.clicked.connect(self.close) self.show() 4 Havaintoja edellisten esimerkkien eroista • Proseduraaliversiossa voisimme antaa argumentteja – Näin aliohjelma olisi yleiskäyttöisempi
    [Show full text]
  • Qte-Doc Documentation Release 0.5.0
    qte-doc Documentation Release 0.5.0 David Townshend September 06, 2012 Contents 1 Key features 3 2 Installation 5 3 Table of contents 7 3.1 Tutorial................................................7 3.2 UIs and Resources..........................................8 3.3 Edit Widgets............................................. 11 3.4 Model/View framework....................................... 14 3.5 Core Tools.............................................. 21 Python Module Index 25 i ii qte-doc Documentation, Release 0.5.0 qte is a wrapper around the PySide GUI toolkit making it simpler and more pythonic to use. No changes are made to the original PySide classes, but new classes and functions are introduced which effectively replace much of the most commonly used PySide GUI functionality. Contents 1 qte-doc Documentation, Release 0.5.0 2 Contents CHAPTER 1 Key features • All objects (i.e. those contained in PySide.QtGui, PySide.QtCore, and the new objects provided by this package) can be imported from a single namespace, e.g: >>> from qte import QRect, QWidget, DataModel Or, more commonly: >>> import qte >>> rect= qte.QRect() The PySide objects, i.e. those prefixed with “Q”, are exactly the same as those imported directly from PySide, all changes are in the new classes. • A number of convenience function had been added. See Core Tools for details. • The PySide model/view framework has been extended and simplified. See Model/View framework for more information. • A new singleton Application class is available, extending the functionality of QApplication. See Application and runApp for more information. •A Document class is provided to manage typical document application functions, such as opening, saving, etc. 3 qte-doc Documentation, Release 0.5.0 4 Chapter 1.
    [Show full text]
  • Rapid GUI Application Development with Python
    Rapid GUI Application Development with Python Volker Kuhlmann Kiwi PyCon 2009 — Christchurch 7 November 2009 Copyright c 2009 by Volker Kuhlmann Released under Creative Commons Attribution Non-commercial Share-alike 3.0[1] Abstract Options and tools for rapid desktop GUI application development using Python are examined, with a list of options for each stage of the tool chain. Keywords kiwipycon, kiwipycon09, Python, GUI, RAD, GUI toolkit, GUI builder, IDE, application development, multi-platform 1 Introduction GUI options are examined for Python with respect to performance, ease of use, runtime, and platform portabil- ity. Emphasis is put on platform-independence and free open source, however, commercial options are included. This paper is a summary of the conference presentation. The related slides are available online[2]. A full paper is planned. The following components of the tool chain are discussed: • Python interpreter • GUI toolkit • IDE (Integrated Development Environment) • GUI builder • Debugger • Database • Testing • Application packaging 2 Python Interpreter Getting the Python interpreter up and running is the easiest part of the tool chain, and is achieved by simply in- stalling the latest stable version for your platform—currently 2.6 or 3.1. The 3.x version is not totally backwards compatible. Pre-compiled packages are available for each platform. For a well-written easy to understand introduction to Python programming, see the book by Hetland[3]. 1 3 GUI toolkit The GUI toolkit provides the graphical user interface (GUI) elements, or widgets, like buttons, scrollbars, text boxes, label fields, tree view lists, file-open dialogues and so on. These widgets are an integral and essential part of the user interface.
    [Show full text]
  • Python Programming — GUI
    Python programming | GUI Finn Arup˚ Nielsen Department of Informatics and Mathematical Modelling Technical University of Denmark October 1, 2012 Python programming | GUI Graphical user interface Tk Python module Tkinter. Quick and dirty. (Langtangen, 2005, Chapters 6 & 11) wxWidgets (wxWindows) wxPython (Ubuntu package python-wxtools) and PythonCard (Ubuntu meta- package pythoncard) Others PyGTK for Gtk, PyQT and PySide for Qt Finn Arup˚ Nielsen 1 October 1, 2012 Python programming | GUI Tkinter Hello world from Tkinter import * def hello(): """Callback function for button press.""" print "Hello World" # Main root window root = Tk() # A button with a callback function Button(root, text="Press here", command=hello).pack() # .pack() method is necessary to make the button appear # Event loop root.mainloop() Finn Arup˚ Nielsen 2 October 1, 2012 Python programming | GUI Tkinter Hello world Finn Arup˚ Nielsen 3 October 1, 2012 Python programming | GUI Tkinter: menu, label Build a GUI for showing one tweet stored in a Mongo database. One tweets at a time. from Tkinter import * import pymongo, re pattern = re.compile(r'\bRT\b', re.UNICODE) Should read from the Mongo database, and display some of the fields in a graphical user interface. With a button the user should be able to click to the next item. Finn Arup˚ Nielsen 4 October 1, 2012 Python programming | GUI A callback function counter = 0 def next(event=None): """Function that can be used as a callback function from a button.""" global counter # Global variable not so pretty counter += 1 tweet
    [Show full text]
  • Object Oriented Interfaces and Pyqt/Pyside Bindings for GR
    Embedding Visualization Applications with PyGR Object oriented interfaces and PyQt/PySide bindings for GR - a universal framework for visualization applications Georg Brandl, Christian Felder, Josef Heinen (a) Microphone Power Spectrum and Peaks (com- (b)Surface Plot with Contour Lines (c)3D Surface Plot puted using FFT) GR PyGR GRaphics Library optimized for real-time data visualizations Object oriented interface on top of GR Manipulating object states instead of fiddling with procedure calls • • • Procedural graphics backend (written in C) Convenience functions for Adding new functionality using derived objects, e.g. • • • Does not rely on creation of figures Zooming Clamp minimum values for selecting a Region of Interest (x , y > 0) • • • min min Panning 1 class ContourAxes(PlotAxes): Representation of continuous data streams • ) Selecting a Region def setWindow(self, xmin, xmax, ymin, ymax): Based on a Graphical Kernel System • if xmin < 1: • Detecting predefined Regions Of Interest (point in polygon test) xmin = 1 Device and Platform independent API • 6 • if ymin < 1: Large scale of logical device drivers/plugins: Independent of GUI Toolkits ymin = 1 • • return PlotAxes.setWindow(self, xmin, xmax, ymin, ymax) Qt, wxWidgets • X11, Quartz, Win32 Drawing a bar at a given position xi, yi to indicate a peak position • • PostScript, PDF, SVG class PeakBars(PlotCurve): • 2 GS (BMP, JPEG, PNG, TIFF) • def drawGR(self): MOV (MPEG4) if self.linetype is not None and self.x: • # preserve old values HTML5 lcolor = gr.inqlinecolorind() • 7 gr.setlinewidth(2) Builtin support for 2D plotting and OpenGL (GR3) gr.setlinecolorind(self.linecolor) • for xi, yi in zip(self.x, self.y): Coexistent 2D and 3D world gr.polyline([xi, xi], [0, yi]) ) 12 # restore old values gr.setlinecolorind(lcolor) QtGR gr.setlinewidth(1) Qt Widgets for drawing and interacting with GR Hide/Unhide dependent objects • • Specialized Qt Events, e.
    [Show full text]