NLP--- How to install the tool NLTK in Ubuntu ?
1. open the website of NLTK and download it.
https://pypi.python.org/pypi/nltk
2. unzip this package and cd:
>>> cd /home/wangxiao/nltk-3.2.4
>>> python setup.py install
## you have installed this software at this point.
>>> python
>>> import nltk ## if it did not show you any error, it denotes you have installed nltk successfully.
>>> nltk.download() ## install the language packages.
>>> select all, then you will see blow ...