Solution:

This most likely indicates that you are missing the “libpq” headers:

should solve the problem

into this:

This particular example allows an easy tracking if a class contains changes. Without the need of calling myclass.get_some_attribute() or myclass.set_some_attribute(foo). You can simply do myclass.some_attribute = foo and the has_changes attribut will change accordingly.

If your class has many attributes, writing custom accessors and mutators can be tedious. So here’s a small Vim-mapping that get’s you started. Sure, you may still need to fine-tune some generated code, but the bulk is there.

Put this into your vimrc, or (like I do) into the ~/.vim/ftplugin/python.vim file so it get’s only loaded for python files. Then you only need to write the attribute name of the class, put your cursor on that line, be sure to be in normal mode (hit a few time <esc>) and hit F6

If you want to change the shortcut, simply change the first parameter to this mapping line.

This will also resize the window, adapting to the desktop size.
Found and adapted from the Qt interest archive.

1. Add the component you want to be scrollable (QFrame, QLabel, …) in the designer as usual
2. In the application code:
   1. Create a new QScrollArea
   2. Set the parent of the widget you created in the designer to “None”
   3. Set the widget of the QScrollArea to the widget from step 1
   4. Insert the QScrollArea to you ui

And here’s some example code (boiled down to the essentials):

You would probably write this somewhere in you application-constructor right after you call setupUi.

This will insert the scroll area at the top of vboxlayout1 (see the doc for insertWidget). You can of course also use addWidget.

It’s a shame that there’s no direct support for QScrollArea in designer. Maybe we will see it in some future release.

An example for C++ can be found in the Qt Forums.

py2exe is a Python Distutils extension which converts Python scripts into executable Windows programs, able to run without requiring a Python installation.

If you run in trouble with sip, read on…

Sure there are other options to create windows executables. The ones I know of:

• Freeze (which comes with python)
• PyInstaller
• cx_Freeze
• py2exe
• ExeMaker

py2exe

The reason why I prefer py2exe, and why I would recommend using it, is because it’s right now the most widely used tool. So you will find lots of hits when googling for it. This is a big bonus. Additionally, it’s configuration is very flexible, and works well with dependancies (let’s say you are using SQLAlchemy, or some other third-party python-module).

The others either did not offer enough flexibility or had trouble detecting imported modules. With Freeze I was not even able to get the program to compile following their example scripts.

py2exe with PyQt

So you have a Qt program written in python and it works on your machine? Great! To get this to work you actually need to have the Qt libraries and the Python interpreter installed. But you don’t necessarily want your end-users to install these. To prevent that, you can use py2exe which will give you a directory with all the required libraries, byte-compiled sources and a ready-to-use windows-executable.

In order to create an executable, you write a standard python distutils setup script:

Then you can create the executable running the setup script with “py2exe” as build target:

With Qt you will run into trouble however. You will most certainly get an error along the lines:

The reason here is that the sip module is required by PyQt, and it’s not found in a place where py2exe could see that. So you need to tell py2exe to include sip even though it does not seem to be imported anywhere:

This will take care of this problem, an your application should run just fine on windows.

Note

py2exe will give you a list of additional dll’s that may be needed. So far I could live without these dll’s. If you want to be on the safe side, you could include those dll’s into your project. But with the python-interpreter and the Qt libraries, your project will already be bloated enough (usually around 20MB). So there’s no need to waste even more space. But, as always, your mileage may vary!

Yes, since version 4, trolltech finally decided to release Qt as well under the GPL. To most of you it’s all old news. But hey…. just felt like writing it down again

The problems with SIP are finally gone. So you just install python, Qt4 and pyqt4 and off you go.

Writing apps is actually a breeze. You fire up the Qt-Designer, drag and drop some widgets on your form, and save the Form as a .ui file.

Next you generate the python-code for the form with pyuic4. Let’s say you created “MainForm.ui”. The you just do:

Actually the name “ui_mainform.py” is fully up to you.

But this script does not have an entry-point, so just typing “python ui_mainform.py” will silently return. For those of you that just thought: “Hey, I read the man-page, and used the “-x” parameter with pyuic4″. Sure. You can do that. But you shouldn’t. Just bear with me a second.

The cleanest way to run your application is to write a startup script. A copy/paste example:

So why not just “pyuic4 -x” ?

Simple. Whenever you run this, you will overwrite your old code. And you will inevitably want to complement your user-interface with some program logic. Otherwise your application won’t do much. So if you put your business-logic into the generated code, you will always end up cutting and pasting things about. And that clearly violates the “Don’t repeat yourself” dogma. So: You be nice, take the startup script and stick your logic in there. Like that you can recreate/regenerate the user-interface from the .ui file without ever (well… nearly) touching yor business-logic-code.

For some programming examples, head right over to Riklaunim’s TechBlog. There’s some most excellent examples for pyqt4. You might see, I “borrowed” the startup script from there too!

A note for Windows users

To get python and Qt working, you need to take care of the version numbers mentioned in the file names of pyqt. Please use the proper Qt version with your pyqt download

As you might have noticed, you also need MingW (a free GNU build environment for windows. Includes C-compiler, libraries, yadda yadda…). Somewhere along the installation, you might get an error nagging you about the win32api. You can happily ignore this and just continue. I have not yet encountered any problems.

On Wed, 22 Oct 2003 12:24:42 -0600
"Justin Johnson" <justinjohnson@fastmail.fm> wrote:

> The general consensus on the mailing list archives seems to be that
> I'd need to setup my code to not require twistd but just run
> standalone.

Uh. *Maybe* that's the consensus, but it's not actually correct. You can
have a tap or tac run as a NT service.

Lets say you have  a script "server.py" that is runnable with "twistd
-y", you can do (and similar code will work for TAPs):

--
Itamar Shtull-Trauring    http://itamarst.org/
Available for Python & Twisted consulting