spaCy/spacy/tokens/spans.pyx

132 lines
4.0 KiB
Cython

from __future__ import unicode_literals
from collections import defaultdict
from ..structs cimport Morphology, TokenC, LexemeC
from ..typedefs cimport flags_t, attr_t
from ..attrs cimport attr_id_t
from ..parts_of_speech cimport univ_pos_t
cdef class Span:
"""A slice from a Doc object."""
def __cinit__(self, Doc tokens, int start, int end, int label=0):
if start < 0:
start = tokens.length - start
if end < 0:
end = tokens.length - end
self._seq = tokens
self.start = start
self.end = end
self.label = label
def __richcmp__(self, Span other, int op):
# Eq
if op == 0:
return self.start < other.start
elif op == 1:
return self.start <= other.start
elif op == 2:
return self.start == other.start and self.end == other.end
elif op == 3:
return self.start != other.start or self.end != other.end
elif op == 4:
return self.start > other.start
elif op == 5:
return self.start >= other.start
def __len__(self):
if self.end < self.start:
return 0
return self.end - self.start
def __getitem__(self, int i):
return self._seq[self.start + i]
def __iter__(self):
for i in range(self.start, self.end):
yield self._seq[i]
property root:
"""The first ancestor of the first word of the span that has its head
outside the span.
For example:
>>> toks = nlp(u'I like New York in Autumn.')
Let's name the indices --- easier than writing "toks[4]" etc.
>>> i, like, new, york, in_, autumn, dot = range(len(toks))
The head of 'new' is 'York', and the head of 'York' is 'like'
>>> toks[new].head.orth_
'York'
>>> toks[york].head.orth_
'like'
Create a span for "New York". Its root is "York".
>>> new_york = toks[new:york+1]
>>> new_york.root.orth_
'York'
When there are multiple words with external dependencies, we take the first:
>>> toks[autumn].head.orth_, toks[dot].head.orth_
('in', like')
>>> autumn_dot = toks[autumn:]
>>> autumn_dot.root.orth_
'Autumn'
"""
def __get__(self):
# This should probably be called 'head', and the other one called
# 'gov'. But we went with 'head' elsehwhere, and now we're stuck =/
cdef const TokenC* start = &self._seq.data[self.start]
cdef const TokenC* end = &self._seq.data[self.end]
head = start
while start <= (head + head.head) < end and head.head != 0:
head += head.head
return self._seq[head - self._seq.data]
property lefts:
"""Tokens that are to the left of the Span, whose head is within the Span."""
def __get__(self):
for token in reversed(self): # Reverse, so we get the tokens in order
for left in token.lefts:
if left.i < self.start:
yield left
property rights:
"""Tokens that are to the right of the Span, whose head is within the Span."""
def __get__(self):
for token in self:
for right in token.rights:
if right.i >= self.end:
yield right
property subtree:
def __get__(self):
for word in self.lefts:
yield from word.subtree
yield from self
for word in self.rights:
yield from word.subtree
property orth_:
def __get__(self):
return ''.join([t.string for t in self]).strip()
property lemma_:
def __get__(self):
return ' '.join([t.lemma_ for t in self]).strip()
property string:
def __get__(self):
return ''.join([t.string for t in self])
property label_:
def __get__(self):
return self._seq.vocab.strings[self.label]