Differences between Qt 4 and PyQt 4

PyQt is a comprehensive set of Python bindings for the Qt framework. However, PyQt 5 is not backward compatible with PyQt 4. It is noteworthy that PyQt 5 does not support any part of the Qt API that are marked as deprecated or obsolete in Qt v5.0. However, it is possible that some of these are included accidentally. If included, they are considered bugs and will be removed when found.

If you are familiar with Qt 4 or have read the first edition of this book, one thing to note is that the signals and slots of are no longer supported. Therefore, the following are not implemented in PyQt 5:

• QtScript
• QObject.connect()
• QObject.emit()
• SIGNAL()
• SLOT()

Also, there is a modification in disconnect() as it no longer takes arguments and will disconnect all connections to the QObject instance when invoked.

However, new modules have been introduced, such as the following:

• QtBluetooth
• QtPositioning
• Enginio

Let's start with a very simple example—calling a window. Again for best performance...