Mark Summerfield [Mark Summerfield] - Rapid GUI Programming with Python and Qt: The Definitive Guide to PyQt Programming

All the tools described in this book are freely available for downloading online. Note, however, that some of the packages are quite large (~50MB for Qt, ~12MB for Python, ~6MB for PyQt, and ~0.5MB for SIP), so they are only really suitable for downloading with broadband connections. In this appendix we cover both downloading and installing, on Windows, Mac OS X, and most X11-based forms of Unix and Unix clones, including Linux and BSD.

All of the packages come with their own installation instructions, which will probably be more up-to-date and comprehensive than those given here, so ideally they are the instructions that you should follow. However, in many cases, this appendix contains sufficient information to get the tools installed and working. One approach would be to use this appendix to identify the packages that need to be obtained (and the order in which they should be downloaded, which matters for Windows users), as well as the order they should be installed (which matters for all platforms). Then, once the tools are downloaded, use the official instructions to install each one, and skim this appendixs instructions to help clarify what needs to be done, as well as to learn a couple of tips, one for Windows users and one for Mac OS X users, that may prove helpful.

For Windows, there are four tools to install: a C++ compiler, the Qt C++ application development framework, the Python interpreter and its accompanying libraries, and PyQt4 (which includes SIP in the Windows binary package). We assume that the GPL editions are being used, in which case the only C++ compiler that will work with Qt is MinGW. (Visual C++ can be used only with the commercial editions of Qt and PyQt and the instructions for installing them are provided when you buy them.)

At the time of this writing, an all-in-one package was under development. This package is an executable setup file that is expected to contain all the PyQt modules (except the QtDesigner module), QScintilla, the translation and Qt Designer support tools, the documentation and examples, the SQLite database, and support for .png, .svg, .gif, and .jpeg image formats. This package is complete and self-contained and requires no other software to be installed apart from Python itself. However, the package is not extensible. If you are learning or evaluating PyQt for the first time, using this package is probably the easiest way to begin. You can always uninstall it and install the precise set of components you need later on when you have gained experience. When the package is available it will be on the Web site http://riverbankcomputing.com. After intalling Python, simply download and execute the all-in-one package to install everything else.

In the instructions that follow, we are using Windows XP Home edition and are installing each component separately. There may be differences for other Windows versions, but they should not be so different that they cant be worked out from whats written here.

The files required for installation are MinGW-3.4.2.exe, qt-win-opensource-4.2.3-mingw.exe, python-2.5.1.msi, and PyQt-gpl-4.2-Py2.5-Qt4.2.3.exe. The books examples are in the file pyqtbook.zip.

The first item to get is PyQt itself. This is because the versions of Python and Qt you will need depend on the version of PyQt you get. Go to http://www.riverbankcomputing.co.uk/pyqt/download.php and download the binary package PyQt-gpl-4.2-Py2.5-Qt4.2.3.exe. The filename has version numbers embedded in it and these may differ from the ones shown here: The first number is the PyQt version which must be at least 4.2 to get the most out of this book; the second number is the Python version that you must get; and the third number is the Qt versionyou must download this precise version.

Now get Qt. Go to http://www.trolltech.com/developer/downloads/qt/index and click the Qt/Windows Open Source Edition link; at the bottom of the page, download qt-win-opensource-4.2.3-mingw.exe. The version number should exactly match the one in the PyQt package name, so if, for example, you downloaded PyQt-gpl-4.3-Py2.5-Qt4.3.1.exe, you will need to get qt-win-opensource-4.3.1-mingw.exe.

The MinGW C++ compiler is also available from Trolltechs Web site, but from a completely different URL. Go to ftp://ftp.trolltech.com/misc/ and download MingGW-3.4.2.exe. (You can skip this step and let the Qt installer download the compiler for you, but by downloading it yourself you have the package in hand, which is more convenient for installing on other machines, or for restoring if your Windows installation goes bad.)

Now it is time to get Python. Go to http://www.python.org/download and download one of the Windows installers. (The ones at the top of the page do not include the source code; this is fine, as you need the source only if you want to modify Python itself.) There may be more than one Windows installer; click a hardware-specific one such as the AMD64 or Itanium one if that matches your machines processor; otherwise click the first onefor example, Python 2.5.1 Windows installer. Save the installer to disk; this will give you a Microsoft Installer filefor example, python-2.5.1.msi. Note that the first two parts of the version number must match the equivalent part of the PyQt version number; so for PyQt-gpl-4.2-Py2.5-Qt4.2.3.exe, any Python 2.5 version is acceptable, such as Python 2.5, or Python 2.5.1, for example.

If you want to run the examples that are shown in the book or you want to see the model answers to the exercises, you can unzip the pyqtbook.zip file available from http://www.qtrac.eu/pyqtbook.html.

Now that all the pieces are at hand, you can perform the installation. The order of installation is important, and is different from the downloading order. (You needed to download PyQt first, to make sure you got the right versions of Python and Qt; but for installing you must start with the C++ compiler, and finish by installing PyQt.) We will assume that the versions are those mentioned earlier, but obviously use whichever versions you downloaded and adjust accordingly.

If you did not download the MinGW installer, either because you have the compiler already installed or because you want the Qt installer to fetch and install it for you, skip to the next paragraph. Otherwise, start up the MinGW installer (e.g., double-click MinGW-3.4.2.exe), and follow the installers instructions. The installers first screen is shown on the left in . The only decision that you must make is where to install MinGW. We have assumed that you accepted the default of C:\MinGW; but you can put it anywhere. If you do not use the standard location, though, make a note of its path since you will need it when you install Qt.

Figure A.1. The MinGW and Qt installers on Windows

To install Qt, start up its installer by double-clicking qt-win-opensource-4.2.3-mingw.exe (or whichever version you downloaded). The installers first screen is shown on the right in put MinGW in the standard location, the Previously installed MinGW path should be correct. If it is not, or if you installed MinGW in a nonstandard location, you must type in its path or use the browse button ( ... ) to locate it. If you did not install MinGW, check the Download and install minimal MinGW checkbox so that the Qt installer can fetch and install it for you.