(The cases in this book are practical, such as campus network search engine, small translation, baidu image crawler and other cases, which can be applied to practical projects with a little modification; There are also cases of wechat robot development through wechat communication protocol, text classification of machine learning, handwriting recognition based on convolutional neural network, and some well-known game cases, such as lianlianliankan, push box, Chinese chess, online Gobang, two person mahjong, character collage, aircraft war games, etc. Learning Python is fun.)