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

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

For those newly moving into the realm of programming, the important question to mull over is what programming language or technology to specialize in. On the other hand, those who are already working as a software developer, the constant worry remains whether their current technology would become obsolete very soon.

Both these concerns could be easily addressed by checking the list of programming languages that are highly in demand and formulating the career by modifying your specialization accordingly. The supply for the developers have not met with the demand in these programming languages yet, making them most viable options for career.

Popular Programming Languages Based on TIOBE Index

The top 10 list of programming languages which are highly in demand in 2014 is listed below in the order of popularity. These languages are identified from the TIOBE Programming Community index which consists of 20 top programming languages. TIOBE index is an indicator of the popularity of programming languages and is updated once in every month.  This index is calculated using multiple search engines, and the ratings are based on the number of skilled engineers world-wide, courses and third party vendors.

The Zen of Python, by Tim Peters has been adopted by many as a model summary manual of python's philosophy.  Though these statements should be considered more as guideline and not mandatory rules, developers worldwide find the poem to be on a solid guiding ground.

Beautiful is better than ugly.
Explicit is better than implicit.
Simple is better than complex.
Complex is better than complicated.
Flat is better than nested.
Sparse is better than dense.
Readability counts.
Special cases aren't special enough to break the rules.
Although practicality beats purity.
Errors should never pass silently.
Unless explicitly silenced.
In the face of ambiguity, refuse the temptation to guess.
There should be one-- and preferably only one --obvious way to do it.
Although that way may not be obvious at first unless you're Dutch.
Now is better than never.
Although never is often better than *right* now.
If the implementation is hard to explain, it's a bad idea.
If the implementation is easy to explain, it may be a good idea.
Namespaces are one honking great idea -- let's do more of those!

If you are interested in using java tutorials to educate yourself from home, you are probably interested in learning how to tell the difference between valuable resource materials, and those which are outdated or incorrect.  Learning to evaluate the quality of available tutorials is both an art and a science, and is best accomplished by paying attention to some of the individual components which make up a quality tutorial.  We will take a look at four of the most important:

·         Good organization – The tutorial needs to have a well-developed structure, which comprehensively details the content it will deliver, and is very easy for users to navigate.  A good organizational structure is indicative of a polished educational thought process, and is more important than you may think in the development of a good tutorial.

·         Valuable content – For good java tutorials, the content should be structured around accomplishing individual tasks.  It should do so by providing clear instruction to the reader, and be concise and to the point as well.  The delivery of quality content is the primary purpose of any tutorial.

·         Attractive appearance – Attention needs to be paid to the manner in which the tutorial is presented.  They should always strive to be visually appealing and not overly busy, so as to distract from communicating the message.  A clean and simple presentation also helps to emphasize the content.