正如Python3代表未来一样，新的《Python Cookbook》版本相比较之前的版本有了一个全新的改变。最重要的是，这个意味着本书是一本非常前沿的参考书。书中所有代码都是在Python3.3版本下面编写和测试的，并没有考虑之前老版本的兼容性，也没有标注旧版本下的解决方案。这样子可能会有争议，但是我们最终的目的是写一本完全基于最新最先进工具和语言的书籍。希望这本书能成为在Python3下编码和想升级之前遗留代码的程序员的优秀教程。(Just like Python3 represents the future, the new version of Python Cookbook has a completely new change compared with the previous version. Most importantly, this means that this book is a very advanced reference book. All the code in the book is written and tested under the Python3.3 version. It doesn't take into account the compatibility of the previous version, nor does it label the old version of the solution. This may be controversial, but our ultimate goal is to write a book based entirely on the latest and most advanced tools and languages. I hope this book can be an excellent tutorial for programmers coding and upgrading legacy code in Python3.)