How can I extract noun phrases from text using spacy?
I am not referring to part of speech tags.
In the documentation I cannot find anything about noun phrases or regular parse trees.
Answer
If you want base NPs, i.e. NPs without coordination, prepositional phrases or relative clauses, you can use the noun_chunks iterator on the Doc and Span objects:
>>> from spacy.en import English
>>> nlp = English()
>>> doc = nlp(u'The cat and the dog sleep in the basket near the door.')
>>> for np in doc.noun_chunks:
>>> np.text
u'The cat'
u'the dog'
u'the basket'
u'the door'
If you need something else, the best way is to iterate over the words of the sentence and consider the syntactic context to determine whether the word governs the phrase-type you want. If it does, yield its subtree:
from spacy.symbols import *
np_labels = set([nsubj, nsubjpass, dobj, iobj, pobj]) # Probably others too
def iter_nps(doc):
for word in doc:
if word.dep in np_labels:
yield word.subtree