In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "We packed our little demo in the DemoPIL class, so that we can extend it easily, while sharing the common code around the demo function, run_fixed_filters_demo."

A block of code is set as follows:

def my_function(x):
    return x*x

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

for a in range(10):
    print a

Any command-line input or output is written as follows:

$ sudo python setup.py install