This section of our beginning python training class always stumps students.  Firstly, because they need to know the difference between a function and a method.  Secondly, they need to understand object oriented programming concepts.  Thirdly, they need to realize that python has three types of methods.  Then they need to know how to use each method, which means they need to know the purpose of each method type.  Then they have to understand mutable versus non-mutable types.  The list goes on.  As part of our python tutorial, I hope to shed some light on this confusing topic.

To begin, the difference between a function and a method in python is that a method is defined within a class.  Here is an illustration:

#function

	def greeting():
	                print "Hello, I hope you're having a great day!"

	class HSGPrinter(object):
	                #method
	                def greeting(self): 
	                                print "Hello, I hope you're having a great day!"

As should be obvious, the second definition of greeting is encapsulated within the HSGPrinter class and is , therefore, refered to as a method.

The astute reader will notice that the greeting method contains one parameter named self.  For those who know C++ , Java or C#, self is equivalent to this i.e. it is a reference to the invoking object:

One of the most recent additions to the iPhone is the Photo Editor, directly in the iPhone. Added in the update that came from Apple over the summer, this new photo editor brings efficiency, and simplicity to photo editing, right in your phone. If you have a photo that you just took a moment ago of you with your friends, and you want to edit some features before posting it on a social networking site, it becomes simpler with this new addition, right in the Photos Application.

Open up the Photos application, and tap on a picture you would like to edit. Once your picture comes up, tap in the top right on the button named “Edit.” A user interface that deals with editing will show up, and you are ready to rock and roll. First off, many times we take pictures at weird angles, we take them sideways, upside down, to the right, to the left, and our phone doesn’t recognize them. In the bottom left, you will see an arrow that is pointing counter clockwise; this is the button that you want to press if you want to flip your picture around to the correct orientation. Keep in mind that this flips counter clockwise, and it doesn’t matter if you pass the orientation that you wanted. Just keep flipping!

Next up is the simple enhance tool. Sometimes colors get drowned out if we don’t have the right lighting in our pictures, and makes the photo look dull, and dreary. You don’t want your colors to look dull and dreary while you are celebrating your trip to New York and seeing Times Square! Tapping on the button that looks similar to a magic wand, your picture will begin to look brighter and fuller. With the tap of a button, the iPhone detects what points in the picture is, as we said earlier, “dull, and dreary” and enhances those colors to their predicted colors, if the light was in the correct intensity. However, if you are dissatisfied with the outcome of the enhance tool, if your picture is not handled well by the phone, you are able to tap on the wand again, and remove your auto enhance.

In the rare case of red eye in your picture, the new photo editor has a solution. Moreover, a one-tap solution. With a simple tap on the red eye correction tool, between the crop tool, and the auto-enhance tool, you bring up a screen where you are now able to tap anywhere on your photo where red eye exists, and remove it. As simple as that. Remember when you had to do crazy dragging, selection, and odd stunts to remove red eye? Not any more.

Here is a list of the organizations that use Python. This list is periodically updated by HSG’s software fans as well as the community at large.
 

Web Development

1.       Yahoo Maps
Yahoo acquired Four11, whose address and mapping lookup services were implemented in Python. Yahoo Maps still uses Python today, as can be seen by examining its URLs.
 

2.       Yahoo Groups
A comprehensive public archive of Internet mailing lists that was originally implemented in pure Python. At one point Scott Hassan, one of the founders of Findmail/eGroups (the company that was later acquired by Yahoo), reported that they had 180,000 lines of Python underlying everything from their 100% dynamic website to all email delivery, pumping out 200 messages/second on a single 400 MHz Pentium.

Memory management is always a priority in pretty much any programming language you would want to use. In the lower level languages such as C, there are a number of functions which help you manage the memory your application uses, but they are not the easiest to use. Some of the more modern programming languages such as Python, Ruby, Perl, and of course the subject of this article, Javascript all have a built in feature called garbage collection.

Garbage collection essentially means that the languages compiler will automatically free the memory being occupied by unused variables and objects, but there is no telling when this could occur. It is purely down to the compiler to decide when the garbage collection process should be initiated.