>>> import nltk

>>> def extract_entities(text):

...     for sent in nltk.sent_tokenize(text):

...         for chunk in nltk.ne_chunk(nltk.pos_tag(nltk.word_tokenize(sent))):

...             if hasattr(chunk, 'node'):

...                 print chunk.node, ' '.join(c[0] for c in chunk.leaves())

...