在本章中介绍的各个模块，提供了各种对字符串的操作。
In addition, Python’s built-in string classes support the sequence type methods described in the Sequence Types — str, unicode, list, tuple, bytearray, buffer, xrange section, and also the string-specific methods described in the String Methods section. To output formatted strings use template strings or the % operator described in the String Formatting Operations section. 此外，还有基于正则表达式操作字符串的re模块。