Book Image

Raspberry Pi for Python Programmers Cookbook - Second Edition

Book Image

Raspberry Pi for Python Programmers Cookbook - Second Edition

Overview of this book

Raspberry Pi cookbook for Python Programmers is a practical guide for getting the most out of this little computer. This book begins by guiding you through setting up the Raspberry Pi, performing tasks using Python 3 and introduces the first steps to interface with electronics. As you work through each chapter you will build up your skills and knowledge and apply them as you progress throughout the book, delving further and further into the unique abilities and features of the Raspberry Pi. Later, you will learn how to automate tasks by accessing files, build applications using the popular Tkinter library and create games by controlling graphics on screen. You will harness the power of the built-in graphics processor by using Pi3D to generate your own high quality 3D graphics and environments. Connect directly to the Raspberry Pi’s hardware pins to control electronics from switching on LEDs and responding to push buttons right through to driving motors and servos. Learn how to monitor sensors to gather real life data and to use it to control other devices, and view the results over the Internet. Apply what you have learnt by creating your own Pi-Rover or Pi-Hexipod robots. Finally, we will explore using many of the purpose built add-ons available for the Raspberry Pi, as well as interfacing with common household devices in new ways.
Table of Contents (18 chapters)
Raspberry Pi for Python Programmers Cookbook - Second Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Hardware and Software List
Index

Creating a self-defining menu


While the previous menu is very useful for defining the most common commands and functions we may use when running the Raspberry Pi, we will often change what we are doing or develop scripts to automate complex tasks.

To avoid the need to continuously update and edit the menu.ini file, we can create a menu that can list the installed scripts and dynamically build a menu from it, as shown in the following screenshot:

A menu of all the Python scripts in the current directory

How to do it…

Create the menuadv.py script using the following code:

#!/usr/bin/python3
#menuadv.py
import os
from subprocess import call

SCRIPT_DIR="." #Use current directory
SCRIPT_NAME=os.path.basename(__file__)

print ("Start Menu:")
scripts=[]
item_num=1
for files in os.listdir(SCRIPT_DIR):
  if files.endswith(".py"):
    if files != SCRIPT_NAME:
      print ("%s:%s"%(item_num,files))
      scripts.append(files)
      item_num+=1
running = True
while (running):
  print ("Enter script number...