Qt for Python UsingQtProperties

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Using Qt Properties in PySide

PySide provides a

Property

function which allows for declaring properties that simultaneously behave both as Qt and Python properties, and have their setters and getters defined as Python functions.

A short example illustrating defining and accessing a Qt property from Python is given below:

from PySide.QtCore import QObject, Property

class MyObject(QObject):
 def ''init''(self,startval=42):
 QObject.''init''(self)
 self.ppval = startval

def readPP(self):
 return self.ppval

def setPP(self,val):
 self.ppval = val

pp = Property(int, readPP, setPP)

obj = MyObject()
obj.pp = 47
print (obj.pp)

The complete specification for PySide's property system is given in "PSEP 103":http://web.archive.org/web/20120423210319/http://www.pyside.org/docs/pseps/psep-0103.html.

Properties in QML expressions

If you are using properties of your objects in QML expressions, QML requires the property to be NOTIFYable. This can be done using a simple signal:

class Person(QtCore.QObject):
 def ''init''(self, name):
 QtCore.QObject.''init''(self)
 self._person_name = name

def _name(self):
 return self._person_name

@QtCore.Signal
 def name_changed(self): pass

name = QtCore.Property(unicode, _name, notify=name_changed)