RE

说明：  作为RE正则表达式的一个最基本，又揽括了大部分知识点的例子程序。把程序运行一遍，然后再根据运行结果理解程序，将会迅速掌握re知识点。(As a basic regular expression RE, embrace include most of the knowledge of the example program. To run the program again, to understand the program and then run the results will quickly grasp the re knowledge.)