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:

Python programming language is general purpose open source programming language. One of its main features is flexibility and ease of use. Python has a variety of useful set of utilities and libraries for data processing and analytical tasks. Currently due to the rise in demand of big data processing python has grown in popularity because its features are easy to use which are core to the processing of huge chunks of information.

Guido Van Rossum, the pioneer of python, introduced python in the year 1980 and then implemented it in 1989. The intention behind the development of python was to make it open source language that can also be used for commercial projects. The fundamental principle of python is to write the code that is easy to use, highly readable and embrace writing fewer lines of code for achieving a particular task. One of the most popular standard libraries which have ready to use tools for performing a various work is Python Package Index. It was introduced in January 2016 and contains more than 72,000 packages for third-party software usage.

Python plays a critical role in linking data to customers. Recently python has found few entry barriers and many people have had access to have experienced the power of python in the past. So, what makes python the best language for big data analytics?

One of the reasons to choose python is that python ecosystem is very vibrant, the ratings at Redmonk are a proof of the strength python community. The Redmonk ranking is based on StackOverflow discussions and contribution made in Github to determine the popularity of programming language on the method used by users to ask questions about Python and the number of the open source projects contributions.

Facebook was originally intended as a way for people to stay in touch with friends and family members by sharing pictures and status updates on their timeline. As the website's popularity has grown, so has criticism that it is becoming one giant, online high school.

Online Bullying

There has been a dramatic increase in recent years in the number of online bullying cases due to the introduction of social media. Bullying isn't just limited to younger Facebook users, either. Many adult users have also resorted to bashing others online through nasty status updates and cruel comments.

Prior to social media, bullying in high school involved "kick me" signs and toilet swirling. Facebook and other social media outlets have allowed users to take bullying to a whole other level. Victims can no longer escape bullying by leaving school or work. The torture continues online, at anytime and anyplace.

Status "Likes"

In high school, everyone wants to be part of the popular crowd; people who are outgoing, beautiful, and seem like they have everything.  Posting a status update is similar to wanting to be popular. Once an update is posted, many users wait with bated breath to see how many friends will "like" their status. They believe that the more "likes" they receive, the more popular they are.

If that isn’t enough, there are many Facebook games that involve "liking" someone's status. Games like "Truth Is", where someone likes a status update and in return the poster writes how they really feel about the friend on their Facebook wall. This can get touchy, especially if the two people aren't friends outside of Facebook. It's similar to high school where someone desperately wants another person to like them, but when they find out how that person really feels they are crushed.

Relationships Are Difficult to Keep Private

When someone signs up for Facebook they’re asked to complete their profile, which includes a relationship section. Users can select from different options including "single", "married", "widowed", and "divorced". Whenever someone changes their relationship status, the update shows up on each of their friend's news feeds.

It's easy to see how this feature correlates with high school where everyone talks about who is dating who or which couple broke up. It used to be that after graduation, people were able to keep their relationships more to themselves. Not so anymore in the age of social media. Now everyone has the ability to state their opinion on a friend's relationship status, either by "liking" their status change or by commenting on it.

Facebook has presented many benefits to its users, including the ability to rekindle old high school friendships. What one must understand when they sign up for the service is that they are opening themselves up to the same criticism and drama that takes place in a high school setting.

Proceed with caution!

In programming, memory leaks are a common issue, and it occurs when a computer uses memory but does not give it back to the operating system. Experienced programmers have the ability to diagnose a leak based on the symptoms. Some believe every undesired increase in memory usage is a memory leak, but this is not an accurate representation of a leak. Certain leaks only run for a short time and are virtually undetectable.

Memory Leak Consequences

Applications that suffer severe memory leaks will eventually exceed the memory resulting in a severe slowdown or a termination of the application.

How to Protect Code from Memory Leaks?

Preventing memory leaks in the first place is more convenient than trying to locate the leak later. To do this, you can use defensive programming techniques such as smart pointers for C++.  A smart pointer is safer than a raw pointer because it provides augmented behavior that raw pointers do not have. This includes garbage collection and checking for nulls.

If you are going to use a raw pointer, avoid operations that are dangerous for specific contexts. This means pointer arithmetic and pointer copying. Smart pointers use a reference count for the object being referred to. Once the reference count reaches zero, the excess goes into garbage collection. The most commonly used smart pointer is shared_ptr from the TR1 extensions of the C++ standard library.

Static Analysis

The second approach to memory leaks is referred to as static analysis and attempts to detect errors in your source-code. CodeSonar is one of the effective tools for detection. It provides checkers for the Power of Ten coding rules, and it is especially competent at procedural analysis. However, some might find it lagging for bigger code bases.

How to Handle a Memory Leak

For some memory leaks, the only solution is to read through the code to find and correct the error. Another one of the common approaches to C++ is to use RAII, which an acronym for Resource Acquisition Is Initialization. This approach means associating scoped objects using the acquired resources, which automatically releases the resources when the objects are no longer within scope. RAII has the advantage of knowing when objects exist and when they do not. This gives it a distinct advantage over garbage collection. Regardless, RAII is not always recommended because some situations require ordinary pointers to manage raw memory and increase performance. Use it with caution.

The Most Serious Leaks

Urgency of a leak depends on the situation, and where the leak has occurred in the operating system. Additionally, it becomes more urgent if the leak occurs where the memory is limited such as in embedded systems and portable devices.

To protect code from memory leaks, people have to stay vigilant and avoid codes that could result in a leak. Memory leaks continue until someone turns the system off, which makes the memory available again, but the slow process of a leak can eventually prejudice a machine that normally runs correctly.

Related:

The Five Principles of Performance

In Demand IT Skills