pyqt: rapid application development
DESCRIPTION
PyQt: rapid application developmentTRANSCRIPT
Qt and C++
Qt is a wonderful piece of software Application multi-platform portability layer Lots of modules and features But... it exposes a C++ API
What's wrong with C++?
Compile/run workflow Manual memory management (Few) testing facilities Wrong frame of mind Steep learning curve
Learning C++ in 21 days
2 words about Python
Object-oriented language Automatic memory management Language uses strong/dynamic typing
Objects have types, references don't
Code is compiled on-the-fly No compile/run workflow
Easy to pick up
Learning Python in 21 14 days
What is PyQt
A binding that maps every Qt class to a Python class
It's not Qt rewritten in Python → Easy to keep in sync with Qt
Developed by Riverbank Software (UK based)
Qt's feature set + Python development speed = profit!
First PyQt program
from PyQt4.Qt import *
app = QApplication([])l = QLabel(“Hello world!”)l.show()app.exec_()
Signal/slot
Any Python callable can be a slot!
from PyQt4.Qt import *
app = QApplication([])
pb = QPushButton("Click me!")pb.show()
def cb(): pb.setText("CLICKED!")
QObject.connect(pb, SIGNAL("clicked(bool)"), cb)
app.exec_()
A simple text editor
Live demo
Reality check
CAD/CAM for fashion design Uses PyQt from day 1 200000 LOC codebase (including tests) In production since 2008, actively mantained
Medical appliance control panel Full rewrite of a 1 man-year C++ application
become unmaintenable Development completed in 3 man months
...many others
PyQt licensing
Qt: GPL / LGPL / commercial PyQt: GPL (no LGPL!) → PyQt GPL:
ok for internal tools ok for open-source software
Otherwise: PyQt commercial license
Urban myths
“Python is too slow to develop real applications!”
FALSE: In a typical PyQt application, the bulk of the running code is “inside” Qt, hence running at C++ speed.
“I must distribute the Python interpreter along with my program source!”
FALSE: you can package your application (PyInstaller), then bundle into a nice graphical installer (InnoSetup)
THANKS !THANKS !
Contacts
Mail: [email protected]
Phone: +39-055-3984627
Fax: +39 178 6003614
http://www.develer.com
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50013 Campi BisenzioFirenze - Italy