Many people had a hand in this work beyond my typing at the keyboard. Some contributed by their effort and others by their sacrifice. Thanks to the team at Packt for their consistent understanding and support. I am particularly thankful to Steven Wilding for help and support above and beyond the call of duty.

Thanks also to Andy Dustman, Geert Vanderkelen, and Swaroop for their helpful review of this book and for making so many significant and helpful recommendations. This book would be much the poorer were it not for their suggestions.

To Richard Goodrich, who first introduced me to Python, thank you for liberating me from bondage to that other P-language. Funny what a little problem can lead to.

My heartfelt thanks and appreciation go to my wife, Michelle, and my sons, Cyrus and Jacob. The latter was born during the writing of this book and consistently brightens even the darkest Scottish weather with his smile. I appreciate your sacrifice. I could not have written this book without your support.

Finally, my thanks to my brother, Larry, who first introduced me to the world of computing. I would probably not know anything about computer programming if you had not left me your TRS-80. So this is all your fault, and I am glad you did it.