NLTK for Named Entity Recognition

Question

I am trying to use NLTK toolkit to get extract place, date and time from text messages. I just installed the toolkit on my machine and I wrote this quick snippet to test it out:

Answer 1

Named entity recognition is not an easy problem, do not expect any library to be 100% accurate. You shouldn't make any conclusions about NLTK's performance based on one sentence. Here's another example:

sentence = "I went to New York to meet John Smith";

I get

(S
  I/PRP
  went/VBD
  to/TO
  (NE New/NNP York/NNP)
  to/TO
  meet/VB
  (NE John/NNP Smith/NNP))

As you can see, NLTK does very well here. However, I couldn't get NLTK to recognise today or tomorrow as temporal expressions. You can try Stanford SUTime, it is a part of Stanford CoreNLP- I have used it before I it works quite well (it is in Java though).