Conventions

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, database table names, folder names, filenames, file extensions, path names, dummy URLs, user input, and Twitter handles are shown as follows: "We start a while True: loop, which will continue until we stop the program." A block of code is set as follows:

 def adxlToRGB(axis):
     axes = adxl345.getAxes(True)
     absADXL = abs(axes[axis])
     if (absADXL >= 1):
         absADXL = 1
     rgbADXL = int(255 * absADXL)
     return rgbADXL

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 adxlToRGB(axis):
     axes = adxl345.getAxes(True)
     absADXL = abs(axes[axis])
     if (absADXL >= 1):
         absADXL = 1
     rgbADXL = int(255 * absADXL)
     return rgbADXL

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

sudo nano /lib/systemd/system/wearableHat.service

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: "Click on the blue Select image button and browse to the Jessie Lite zip archive you just downloaded"

Warnings or important notes appear like this.

Tips and tricks appear like this.