Invoking an external command in Python is a two step process:

from subprocess import call
call(["ls","-1"])

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:

Is it possible for anyone to give Microsoft a fair trial? The first half of 2012 is in the history books. Yet the firm still cannot seem to shake the public opinion as The Evil Empire that produces crap code.

I am in a unique position. I joined the orbit of Microsoft in 1973 after the Army decided it didn't need photographers flying around in helicopters in Vietnam anymore. I was sent to Fort Lewis and assigned to 9th Finance because I had a smattering of knowledge about computers. And the Army was going to a computerized payroll system.

Bill and Paul used the University of Washington's VAX PDP computer to create BASIC for the Altair computer. Certainly laughable by today's standards, it is the very roots of the home computer.

Microsoft became successful because it delivered what people wanted.

The future looks just as bright for information technology as it did ten years ago when this career field started growing in huge numbers due to major internet technological advances and the popularity of mobile devices such as the smartphone and eReaders like Amazon’s Kindle.  In classrooms and libraries across the nation, information technology has become instrumental in the way students learn and the way teachers give lessons, and thanks to online education more adults have access to a better education without incurring a lot of debt. Needles to say, the need for qualified workers in information technology will continue in times to come. Some of the technological careers that are rapidly growing in popularity in the last decade are a direct reflection of current trends.

Information Technology Managers

The information technology manager is responsible for handling all computer activities for a business and performs upgrades on computer software and hardware, installs new security features on computers, creates budgets and goals for the IT department, supervises other IT employees and troubleshoots computers when needed. According to the Bureau of Labor Statistics, there were 332,700 information technology management jobs filled in 2012 and a majority of these positions were in the computer systems sector. Most information technology managers hold a bachelor's degree in computer science or information technology, and a growing number of employers prefer a graduate degree. The job growth is expected to grow at 15% between now and 2022.

Mobile Application Developers

This job will grow by leaps and bounds as millions of people continue to purchase mobile devices and download apps for business and entertainment purposes. It creates expanded opportunities for those who want to become mobile application developers. A mobile application developer often works with other developers to create mobile-friendly apps or mobile-friendly versions of business websites for consumers. The developer may have his own firm or he may be employed with a larger company, and he will need to understand the basics of web design and different kinds of codes to succeed in this career. The Bureau of Labor Statistics states that the job growth is expected to be at 28% by 2020.

Health Information Technology

Another fast growing sector within information technology is health information technology and there are various jobs to choose from. You can work with health insurance providers and your duties would include processing patients' insurance claims and managing patients' insurance information using a computer database. Another option is to work as a medical biller in a doctor's office preparing patient’s invoices. The good thing about these jobs is that you do not need a four-year degree to get the training; you can obtain a two-year associates degree or a certificate in health information technology.

Search Engine Optimization Consultant

This is an important information technology career because most businesses have websites and if these websites are going to receive high traffic from visitors and earn profit, proper search engine optimization is necessary. The SEO consultant's job is to ensure that a business website gets high rankings on the major search engines and plenty of traffic from visitors. A good SEO consultant at a minimum will know how to research keywords effectively and implement these into the website's content based on the website's theme and he would utilize web analytics as part of the job. An SEO consultant may work on a freelance basis or be employed with an advertising company as an example.

Best Cities for Technology Careers

If you're thinking about relocating for your career, here are some of the best cities currently for information technology jobs listed in Forbes.