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

Code words in text are shown as follows: "Be very careful when using the sudo command."

A block of code is set as follows:

def count(maximum):
    value = 0
    while value < maximum:
        value = value + 1
        print "value =", value

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

def count(maximum):
    value = 0
    while value < maximum:
        value = value + 1
        print "value =", value

Any command-line input or output are written as:

sudo apt-get upgrade

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "Select Raspbian and click on Install."