クジラ本 python yaml nltk nltk.download()

NLP 
import nltk
=>error..

So, I install PyYAML from
http://pyyaml.org/wiki/PyYAML

OK.
import nltk
nltk.download()
=> It works! And I downloaded 'book' from appeared GUI.

After downloading, I type
from nltk.book import *
len(text1)
=>260819 !! Very long text I got.

DATA IS READY!