python nltk 学习笔记(1)

from nltk.book import *

>>> type(text1)

<class 'nltk.text.Text'>

http://nltk.googlecode.com/svn/trunk/doc/api/nltk.text.Text-class.html

text1.concordance("monstrous")

text1.similar("monstrous")

sorted(set(text3))

>>> f = FreqDist(text1)

>>> f

<FreqDist with 19317 samples and 260819 outcomes>

http://nltk.googlecode.com/svn/trunk/doc/api/nltk.probability.FreqDist-class.html

>>> v = f.keys()

>>> type(v)

<type 'list'>

>>> V = set(text1)

>>> len(V) == len(v)

True

 

>>> long_words = [w for w in V if len(w) > 15]

>>> sorted(long_words)

Function	Meaning
s.startswith(t)	test if s starts with t
s.endswith(t)	test if s ends with t
t in s	test if t is contained inside s
s.islower()	test if all cased characters in s are lowercase
s.isupper()	test if all cased characters in s are uppercase
s.isalpha()	test if all characters in s are alphabetic
s.isalnum()	test if all characters in s are alphanumeric
s.isdigit()	test if all characters in s are digits
s.istitle()	test if s is titlecased (all words in s have have initial capitals)

 

 

bigrams(text1)

>>> [w.upper() for w in s]  //cap all elements

>>> len(set([word.lower() for word in text1]))