Pyobjc And Cocoa On Snow Leopard

I am about to start my A-Level Computing project (High School Level) which will hopefully be a point-of-sale application for Mac OS. Unfortunately, Objective-C is a little out of

Solution 1:

Allow me to echo what has already been said. I too am a student who just started a Cocoa development project, and at the beginning I thought "Well, I already know Python, I'll just use PyObjC and save myself from having to learn Objective-C, which looks beyond my grasp." I learned quickly that it can't be done. You can develop for OS X without learning Objective-C, but not without learning the Cocoa libraries, which constitute 99% of what you need to learn to write a Cocoa app in Objective-C. Objective-C itself isn't that hard; it's the Cocoa libraries that you need to invest in learning.

PyObjC basically uses Cocoa libraries and Python syntax. I gave up with it quickly and decided that if I was going to have to learn Cocoa, I may as well use Objective-C.

If you're looking to learn, Aaron Hillegass's book is a good place to start. Good luck!

Solution 2:

You mean like Checkout? :-) I only mention it because Checkout is gorgeous and written with PyObjC...

Your concerns are valid, although probably not as much of a potential showstopper as you'd think. Using PyObjC still requires you to learn some Objective-C, and definitely requires you to understand at least some of the Cocoa frameworks, since you need to call into the Cocoa frameworks whenever you need to do some sort of Cocoa-specific task.

I recommend you read and consider the SO question "Why is the PyObjC documentation so bad?" and "PyObjc vs RubyCocoa for Mac development: Which is more mature?" before you completely convince yourself that "just PyObjC" will make things much easier. I refuse to disparage PyObjC because it is quite powerful and incredibly useful, but realize that nothing is a silver bullet, and no language or technology is best for all problems.

The Objective-C language is simple and pretty straightforward. The Cocoa frameworks generally dominate the learning curve for new Cocoa programmers. Plus, you have StackOverflow and lots of other resources to help answer your questions. (Judging by the activity of the "pyobjc" tag, you also stand a better chance of getting good Objective-C help on SO.)

Solution 3:

And as one of the Checkout developers I'll weigh in too (hi Quinn!). From what we've seen PyObjC runs fairly well on Snow Leopard. We've built one of the latest SVN revisions 2.2b with some customizations on Leopard and just moved over the site-packages folder.

Theoretically you should be able to use the built in Python/PyObjC (just do import objc, Foundation, AppKit) but as we ship/work with custom versions of both Python and PyObjC I'm not sure what the status exactly is. The mailing list doesn't mention a lot of people having issues (just a few) so that could be a good sign.

Good luck with the project, and if you have specific POS questions shoot me an email ;-)

Solution 4:

I hardly use PyObjC myself, but I believe you need to run the Xcode installer on the Snow Leopard DVD in order to use PyObjC.

Also, as Quinn said, you will need to understand at least some Objective-C in order to use a Cocoa bridge like PyObjC without tearing your hair out. It just doesn't insulate you that completely.

Solution 5:

I'm going to agree with Quinn here. Even if you're already proficient in Python, learning how to interface Python and Cocoa is not going to be any easier than learning Cocoa with Objective-C.

Objective-C is a simple, clean language that is quite easy to grok. Building the GUI and hooking it up to the back-end will be harder than learning the Objective-C to write the back-end, and building the GUI and hooking it up isn't that hard.

Follow the Cocoa app tutorial (you should be able to get through it in a day, or maybe a weekend if you go slow) and you'll be well on your way.