Develop Reference

How can I have a Macro like recording feature for PyQt

I have a Qt tablewidget and other Qt widgets adjoining it. What I am looking for a Automatic script generator that records all the actions that I would perform on the table or other Qt widgets. I had also worked with Enthought and they have a wonderful apptool enthought.scripting that helps me with the same but only for traits objects. I would like to do the same on PyQt widgets but dont know how.

This is one of those ideas that seems so natural, it makes you wonder why there isn't already a library out there that does it.
Well, it turns out that writing something that gets you 80% of the solution is pretty straightforward, especially if your app is small. But implementing a recording/playback system that works for a large app with a diverse array of widgets is quite a pain.
I wrote a library that does its best to solve this problem. It's full of hacks, and the code is still very immature (I just pushed the repo to github today), but you might get some ideas. Heck, if you're lucky, you might even be able to use it without any changes:
https://github.com/stuarteberg/eventcapture
There's no documentation yet. I plan to explain all the tricks to get this working, and probably clean up the code a bit. For now, you can at least get started by trying the demo as described in the Readme.

You could use the eventFilter method from your QApplication instance.

What's a good resource to build my first python project?

I'm tired of books and tutorials who walk me through how to print things before I can do anything fun. I want to build simple apps or programs. Any suggestions for where to start so I can make and learn at the same time?

If you're just looking for something to do that will challenge you to start actually using Python rather than reading about it, try the Ruby Quiz. You don't have to use Ruby to create solutions.
Each quiz is a problem that can be scripted (using any language, really). Ideally it'll force you to apply the concepts you've been reading about to "real life" problems.

If you are tired of tutorials, then just start building something. Anything. If you get stuck, glance back over the tutorials, or consult the documentation. I'm a big fan of learning by doing.
A short list of options from off the top of my head:
If you're into web development, Django is a popular python web framework that is very well documented. The Blog app is a popular starting point.
Python itself is pretty well documented. If you're a complete beginner to python AND programming in general, you may want to try something less complex. Pick a random task and try to do it using python:
Read and print the ID3 tags from all your mp3 files using mutagen.
List or download your email using the python imaplib or poplib modules.
Write a zip/unzip utility using zipfile.
Don't be in too much of a hurry, and be realistic. Unless you've got a pile of programming under your belt, you won't be able to jump into a complex project after reading a few tutorials. Patience and practice will get you to the place where you can tackle really interesting projects. Impatience will merely lead to frustration.

Might i suggest pygame http://www.pygame.org/news.html ? If you want to do things with visuals, your not going to get anywhere with the default python modules unless, of course you know how to implement SDL. As stated above in the comments, the tutorials are there for a reason; although they are simple, they are meant to teach you the basics and perhaps, have you think about ideas of implementing such given tools to larger projects. Give pygame I try. You can create a window with lines and shapes in a little as ~10 lines. From there you can expand your knowledge to Object-Oriented programming(which a must for UI) and be on your way to larger projects such as AI, graphics, etc.
P.S. Check this book out http://apress.com/book/view/1590598725. Although you might not want to get into game development, it will teach you some rather useful techniques which may help your research in application development.

Looking for advice on how to develop applets for Gnome / Ubuntu

I am a linux (mostly ubuntu) user with a reasonable understanding of how the system works (although I am certainly not a linux guru!). In the past I have developed small cross-platform desktop applications in python/GTK and I delivered them to clients as self-contained filetrees, so that the only dependencies were Python itself and GTK.
Now I would like to develop a small applet for ubuntu, that I would like to release under GPL 2 or 3.
In particular these are the new steps I know I must learn in order to achieve my goal (it is very possible there are a few more that I am unaware of, though!):
Integrating with gnome: I want my application to be available as an applet in the taskbar.
Using D-bus: In particular I want my applet to use the new osd-notification framework for ubuntu, but communication with other applets is also a possible feature for a second iteration.
Packaging: I would like to setup a public PPA as soon as the application will reach alpha stage, but I also would like to use dependencies from existing packages in the official repos, rather than include the libraries again in my own package.
Of course official documentation will be my first source of knowledge, but - basing my judgment on the very useful answers that I received on another topic here on SO - I decided to turn to the SO community to collect additional advice like for example:
Are there additional steps to those I outlined before, that I have to learn in order to be able to implement my project?
Based on your own experience, would you advise me to learn those steps in advance (as the knowledge of those will influence my way of coding the core functionality) or would you consider integration with gnome / d-bus and packaging as "higher encapsulating levels" that can be added on top of core functionality afterwards (note: D-bus will be used at first just for pushing data. Input data will be retrieved with a webservice)?
Would you advise me to separate my application in two packages (back-end and front-end) or to keep it together in a single package?,
Do you know of any useful resource that you would advise me to look at, for learning any of the things that I have to?
Are you aware of any common "beginner's mistakes" that I should be aware of?
These questions are not meant to be exhaustive, though: if you feel that I am missing something from the general picture, you are more than welcomed to point me in the right direction!
PS: Should I have failed in explaining my final goal, take a look at project hamster: what I want to achieve is similar in terms of user interface (meaning: the applet should display the status and clicking on it should open the application itself, from which you could both configure the applet and perform various operations).

Well, you list python, so you'll want to have pynotify in your arsenal. It wraps DBus, and gives you a direct api for manipulating the osd-notification system.
>>> import pynotify
>>> pynotify.init("Lil' Applet")
True
>>> note = pynotify.Notification(
... pynotify.get_app_name(),
... "Lil' Applet wants you to know something's up.",
... "/usr/share/icons/Human/48x48/status/dialog-information.png")
>>> note.show()
True
This displays a notification that looks like this:
[ ] **Lil' Applet**
[ICON]
[ ] Lil' Applet wants you to know something's up.

As you already know, your first and best friend will be the code written by others - copy, paste, dissect, understand.
Luckily there are a few projects that do what you intend to achieve.
I can recommend conduit's code as a prime reference how to do things in a clean fashion. I think they also have stuff on dbus. Others to keep an eye on, would be deskbar-applet, hamster (heh), and any other app you remember having feature X. Sometimes it might require some C code deciphering though (like the applet button bit - i suggest you better take it from hamster as i was having some major time getting the thing straight)
Then the "devhelp" app will be of great assistance - it allows you to read and search in man pages fast and easy. Make sure that you also have the -doc packages for all the modules you intend to use.
For user interface i strongly suggest using glade, as that will allow you to change interface later much easier. Where you can't use glade - add and alignment box and add the widget in the box in the code.
There certainly will be quirks and things that you will learn the hard way. Should not be too hard though!
The packaging, especially the autotools will be bit of a struggle, but you will get it right. For how to do debians (and from there to PPA), you can dig in the hamster's repository history. There was once a "debian" folder.
I would suggest to start small - see if you can get a window. Then put a button on it.
You don't have to do it "right" the first time. For first time it will be ok, if something works at all.
As for the separation - i would not bother about it until you get there. Splitting up into two parts and have a core, should not be too hard later. But that all depends on your priorities.
Last thing - getting friends who know the field helps too. And one way to get new friends, is by taking part in other projects, heh.

There are some very good recommendations here already, but let me suggest that you develop your applet not so much "for Ubuntu" as "for Gnome". It doesn't take much extra effort to also make RPM packages for distributions such as Fedora, and Arch Linux packages, to name two examples. There is one major disadvantage though -- to stay compatible with Debian stable you have to stick to ancient versions of GTK and GLib, or at least make any functionality depending on newer versions optional. It's painful, but apparently Debian stable users appreciate it.
I'd also suggest setting up a source code management system somewhere as early as possible. You may not be worried about your disk crashing, but sometimes it saves you a lot of trouble just to be able to revert everything you did since the last commit.
Here's the link to the documentation on the official Gnome Panel Applet library. I don't know if it has Python bindings or not.

When I asked this question two years ago Ubuntu and Gnome were much closer to each other than they are today. At present (end of 2011) gnome adopted the gnome-shell, while Canonical decided to develop their very own UI (unity)...
Part of the tension that brought to the split specifically involved libappindicator, which makes the way I formulated this question (and probably part of the answers) obsolete.
Besides, there is now AskUbuntu on stack exchange, that would probably be a much better forum to ask about ubuntu-specific question.

Is there a good diagramming library for Python?

I should say I'm looking for something interactive, equivalent to what Nevron offers in it's .NET Diagram product, where a user can create nodes, interact with them by dragging them around, etc. I know there's GraphViz, but as far as I know it's static, and just renders a graph/diagram, there is no interaction with it.
I have a bad feeling there is nothing as rich as this in the cross platform world for Python or any other script language, but maybe I've missed it.

Ubigraph is probably not what you want, but is still really excellent.

I have been searching for a solution to this myself for quite some time, and have just come across an Apache 2.0 licensed project based on Cairo and GTK, called Gaphas.
It has diagram widgets allowing user placement and interaction, and appears to be quite active.
There's also a python-code generated diagram library (appropriately, and perhaps confusingly) called Diagrams, which you may be able to borrow from, though doesn't appear interactive.

Writing graphviz dot files is a good way to go. Google for graphviz and see http://code.google.com/p/pydot/ for a python wrapper.

Is there a Python library that allows to build user interfaces without writing much code?

I am writing editing front ends in Python since several years now, and I am fed up with micromanaging every UI detail of a window or dialog every single time.
Is there a technology that allows me to, say, specify the relations between a GTK+ Glade-designed interface and the tables and records of an SQLite database to do all the middle man work? It should spare me the work of manually writing event handlers, input evaluators and view updates.
The technologies in question are just examples, but I want to stick with Python as far as possible.

Besides the ones already mentioned I can add:
Kiwi
uxpython
pygtk
treethon
I've never used any of them so have no recommendations but, for what it's worth, I have used at least 2 complex programs built directly on pygtk that worked in both Windows and Linux.
I think Kiwi is the only one of these with baked in support for db (through interface with SQLAlchemy, SQLObject, or Storm) but I would be surprised if you couldn't use one of those ORM's inside any of the other frameworks.

PyQt and its models can automate some of these tasks for you (to some amount off course, e.g. filling widgets with data from a database and handling most of the widgets behaviour, buffering etc.).
If you want a more object-oriented approach to handling SQL you could look into an ORM-oriented solution (for example SQLAlchemy).

Dabo is built on top of wxPython, so you may not prefer it, but it's designed to make it easy to tie a GUI to a database, so I'd recommend you check it out if you haven't already. In particular, it's got good facilities for tying widgets to data, and handling a lot of the common cases of GUI development.

wxGlade may help, although I haven't used it myself so I don't speak from experience.
Boa Constructor apparently has a wxPython GUI builder in it, and there is also PythonCard, though development on these two projects seems to have stalled.

Traits might be a good option for you.
http://code.enthought.com/projects/traits/docs/html/TUIUG/index.html
AS simple as it is to map a UI to an object, it doesn't seem too far fetched to incorporate SQLAlchemy for persistence.

There is a good book on wxPython, "wxPython in Action", which can't be said for some of the other solutions. No knock on the others. I've had success developing with wxPython in the past and it comes with a great set of demo applications with source code from which you can borrow liberally.
The best UI designer I found for wxPython applications is a commercial one, Anthemion DialogBlocks. It's by one of the wxPython programmers and is worth the money. Other solutions for UI design include wxGlade (I found it usable but not featureful) and Boa Constructor (haven't used it). Wing IDE might also have one. Stani's Python Editor bundles wxGlade, I believe. There are a lot of other projects that don't really work or are fairly old.
As far as SQL automation goes, as another answerer says, I'd look at SQL alchemy, but the learning curve for a small application might be too much and you'd be better off just going straight to odbc. The best odbc api is the one used by Django, pyodbc.
It's been a while since I developed with these tools, so there may be something newer for each, but at the time these were definitely the best of breed in my opinion.

I had lots of success with wxPython, but that was some years ago now and there may be better new solutions...

Ok this is an unconventional solution but write yourself a code generator. I have done this several times using Mako. So in my case I auto inspect a table which columns it contains and types and generate classes from that. It's more work upfront but does exactly what you want and is reusable in subsequent projects.