Checking to see if a file exists is a two step process in Python. Simply import the module shown below and invoke the isfile function:

import os.path
os.path.isfile(fname)

There has been and continues to be a plethora of observational studies by different researchers in the publishing industry focused on how e-books have affected hard-copy book sales. Evidence from these studies has indicated that there is a significant and monumental shift away from hard-copy books to e-books.[1]These findings precipitate fears that hard-copy books might become more expensive in the near future as they begin to be less available.  This scenario could escalate to the point where only collectors of hard-copy books are willing to pay the high price for ownership.

The founder of Amazon, Jeff Bezos, made a statement in July 2010 that sales of digital books had significantly outstripped U.S. sales of hard-copy. He claimed that Amazon had sold 143 digital books for its e-reader, the Kindle, for every 100 hard-back books over the past three months. The pace of this change was unprecedented;  Amazon said that in the four weeks of June 2010, the rate of sales had reached 180 e-books for every 100 hard-backs sold. Bezos said sales of the Kindle and e-books had reached a "tipping point", with five authors including Steig Larsson, the writer of Girl with a Dragon Tattoo, and Stephenie Meyer, who penned the Twilight series, each selling more than 500,000 digital books.[2] Earlier in July 2010, Hachette said that James Patterson had sold 1.1m e-books to date.

According to a report made by Publishers Weekly, for the first quarter of 2011, e-book sales were up 159.8%; netting sales of $233.1 million. Although adult hard-cover and mass market paperback hard-copies had continued to sell, posting gains in March, all the print segments had declined for the first quarter with the nine mass market houses that report sales. Their findings revealed a 23.4% sales decline, and that children’s paper-back publishers had also declined by 24.1%.[3] E-book sales easily out-distanced mass market paperback sales in the first quarter of 2011 with mass market sales of hard-copy books falling to $123.3 million compared to e-books’ $233.1 million in sales.

According to .net sales report by the March Association of American Publishers (AAP) which collected data and statistics from 1,189 publishers, the adult e-Book sales were $282.3 million in comparison to adult hard-cover book sales which counted $229.6 million during the first quarter of 2012. During the same period in 2011, eBooks revenues were $220.4 million.[4] These reports indicate a disconcerting diminishing demand for hard-copy books.

A string in Python is enclosed in either single or double quotes.  Therefore, either one does the trick.  A common practice is to place single words with no characters that can be interpolated in single quotes and multi-word strings that contain interpolated characters in double quotes.  This may be a carry over from Perl where interpolated characters are in double quotes. 

If you do not want to interpolate a string, use a raw string ... r"\n".  With the exception of the last print statement, each of the print statements prints hello on a separate line from how are you?.  They are great for regular expressions.

Finally, triple double quotes """ some message about a function or class ... """ are used for docstrings.

print "hello \n how are you?"
print 'hello \n how are you?'
print r"hello \n how are you?"

Smart Project Management –Best Practices of Good Managers

Project management could be one of the easiest jobs on the planet, and could also be the worst nightmare. The difference between the two extremes depends on smart management of a project. According to the project management institute, there are five phases in project management - Initiating, Planning, Executing, Monitoring & Controlling, and Closing.

Every manager has his own style of project management. But there are a lot of contributing factors that result in a successfully managed project. These factors vary from project to project, but they all contain some common elements.

1. Setting SMART Goals