摘要： CHAPTER 5 Categorizing and Tagging Words 分类和标注单词 Back in elementary school you learned the difference between nouns, verbs, adjectives, and adverbs. These “word classes” are not just the idle invention of grammarians（文法家）, but are useful categories for many language processing tasks. As we will s... 阅读全文

摘要： 4.11Exercises 练习 ☼ Find out more about sequence objects using Python's help facility. In the interpreter, typehelp(str),help(list), andhelp(tuple). This will give you a full list of the functions supported by each type. Some functions have special names flanked with underscore... 阅读全文

摘要： 4.10Further Reading 深入阅读 This chapter has touched on many topics in programming, some specific to Python, and some quite general. We've just scratched the surface（我们还停留在肤浅的表面）, and you may want to read more about these topics, starting with the further materials for this chapter available athttp 阅读全文

摘要： 4.9Summary小结 Python's assignment and parameter passing use object references; e.g. ifais a list and we assignb = a, then any operation onawill modifyb, and vice versa. Python的赋值和传参使用了对象引用；例如，如果a是一个列表并且我们赋值b=a，那么任何对于a的操作将会修改b 的值，反之亦然。 Theisoperation tests if two objects are i... 阅读全文

摘要： 4.8A Sample of Python LibrariesPython库的样本 Python has hundreds of third-party libraries, specialized software packages that extend the functionality of Python. NLTK is one such library. To realize the full power of Python programming, you should become familiar with several other libraries. Most of . 阅读全文