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spaCy/spacy/tokenizer.pyx
Sofie 46dfe773e1 Replacing regex library with re to increase tokenization speed (#3218) 
* replace unicode categories with raw list of code points

* simplifying ranges

* fixing variable length quotes

* removing redundant regular expression

* small cleanup of regexp notations

* quotes and alpha as ranges instead of alterations

* removed most regexp dependencies and features

* exponential backtracking - unit tests

* rewrote expression with pathological backtracking

* disabling double hyphen tests for now

* test additional variants of repeating punctuation

* remove regex and redundant backslashes from load_reddit script

* small typo fixes

* disable double punctuation test for russian

* clean up old comments

* format block code

* final cleanup

* naming consistency

* french strings as unicode for python 2 support

* french regular expression case insensitive
2019-02-01 18:05:22 +11:00

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Cython
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# cython: embedsignature=True
# cython: profile=True
# coding: utf8
from __future__ import unicode_literals
from collections import OrderedDict
from cython.operator cimport dereference as deref
from cython.operator cimport preincrement as preinc
from cymem.cymem cimport Pool
from preshed.maps cimport PreshMap
import re
cimport cython
from .tokens.doc cimport Doc
from .strings cimport hash_string
from .errors import Errors, Warnings, deprecation_warning
from . import util
cdef class Tokenizer:
"""Segment text, and create Doc objects with the discovered segment
boundaries.
"""
def __init__(self, Vocab vocab, rules=None, prefix_search=None,
suffix_search=None, infix_finditer=None, token_match=None):
"""Create a `Tokenizer`, to create `Doc` objects given unicode text.
vocab (Vocab): A storage container for lexical types.
rules (dict): Exceptions and special-cases for the tokenizer.
prefix_search (callable): A function matching the signature of
`re.compile(string).search` to match prefixes.
suffix_search (callable): A function matching the signature of
`re.compile(string).search` to match suffixes.
`infix_finditer` (callable): A function matching the signature of
`re.compile(string).finditer` to find infixes.
token_match (callable): A boolean function matching strings to be
recognised as tokens.
RETURNS (Tokenizer): The newly constructed object.
EXAMPLE:
>>> tokenizer = Tokenizer(nlp.vocab)
>>> tokenizer = English().Defaults.create_tokenizer(nlp)
"""
self.mem = Pool()
self._cache = PreshMap()
self._specials = PreshMap()
self.token_match = token_match
self.prefix_search = prefix_search
self.suffix_search = suffix_search
self.infix_finditer = infix_finditer
self.vocab = vocab
self._rules = {}
if rules is not None:
for chunk, substrings in sorted(rules.items()):
self.add_special_case(chunk, substrings)
def __reduce__(self):
args = (self.vocab,
self._rules,
self.prefix_search,
self.suffix_search,
self.infix_finditer,
self.token_match)
return (self.__class__, args, None, None)
cpdef Doc tokens_from_list(self, list strings):
deprecation_warning(Warnings.W002)
return Doc(self.vocab, words=strings)
@cython.boundscheck(False)
def __call__(self, unicode string):
"""Tokenize a string.
string (unicode): The string to tokenize.
RETURNS (Doc): A container for linguistic annotations.
"""
if len(string) >= (2 ** 30):
raise ValueError(Errors.E025.format(length=len(string)))
cdef int length = len(string)
cdef Doc doc = Doc(self.vocab)
if length == 0:
return doc
cdef int i = 0
cdef int start = 0
cdef bint cache_hit
cdef bint in_ws = string[0].isspace()
cdef unicode span
# The task here is much like string.split, but not quite
# We find spans of whitespace and non-space characters, and ignore
# spans that are exactly ' '. So, our sequences will all be separated
# by either ' ' or nothing.
for uc in string:
if uc.isspace() != in_ws:
if start < i:
# When we want to make this fast, get the data buffer once
# with PyUnicode_AS_DATA, and then maintain a start_byte
# and end_byte, so we can call hash64 directly. That way
# we don't have to create the slice when we hit the cache.
span = string[start:i]
key = hash_string(span)
cache_hit = self._try_cache(key, doc)
if not cache_hit:
self._tokenize(doc, span, key)
if uc == ' ':
doc.c[doc.length - 1].spacy = True
start = i + 1
else:
start = i
in_ws = not in_ws
i += 1
if start < i:
span = string[start:]
key = hash_string(span)
cache_hit = self._try_cache(key, doc)
if not cache_hit:
self._tokenize(doc, span, key)
doc.c[doc.length - 1].spacy = string[-1] == ' ' and not in_ws
return doc
def pipe(self, texts, batch_size=1000, n_threads=2):
"""Tokenize a stream of texts.
texts: A sequence of unicode texts.
batch_size (int): Number of texts to accumulate in an internal buffer.
n_threads (int): Number of threads to use, if the implementation
supports multi-threading. The default tokenizer is single-threaded.
YIELDS (Doc): A sequence of Doc objects, in order.
"""
for text in texts:
yield self(text)
def _reset_cache(self, keys):
for k in keys:
del self._cache[k]
cdef int _try_cache(self, hash_t key, Doc tokens) except -1:
cached = <_Cached*>self._cache.get(key)
if cached == NULL:
return False
cdef int i
if cached.is_lex:
for i in range(cached.length):
tokens.push_back(cached.data.lexemes[i], False)
else:
for i in range(cached.length):
tokens.push_back(&cached.data.tokens[i], False)
return True
cdef int _tokenize(self, Doc tokens, unicode span, hash_t orig_key) except -1:
cdef vector[LexemeC*] prefixes
cdef vector[LexemeC*] suffixes
cdef int orig_size
cdef int has_special = 0
orig_size = tokens.length
span = self._split_affixes(tokens.mem, span, &prefixes, &suffixes,
&has_special)
self._attach_tokens(tokens, span, &prefixes, &suffixes)
self._save_cached(&tokens.c[orig_size], orig_key, has_special,
tokens.length - orig_size)
cdef unicode _split_affixes(self, Pool mem, unicode string,
vector[const LexemeC*] *prefixes,
vector[const LexemeC*] *suffixes,
int* has_special):
cdef size_t i
cdef unicode prefix
cdef unicode suffix
cdef unicode minus_pre
cdef unicode minus_suf
cdef size_t last_size = 0
while string and len(string) != last_size:
if self.token_match and self.token_match(string):
break
last_size = len(string)
pre_len = self.find_prefix(string)
if pre_len != 0:
prefix = string[:pre_len]
minus_pre = string[pre_len:]
# Check whether we've hit a special-case
if minus_pre and self._specials.get(hash_string(minus_pre)) != NULL:
string = minus_pre
prefixes.push_back(self.vocab.get(mem, prefix))
has_special[0] = 1
break
if self.token_match and self.token_match(string):
break
suf_len = self.find_suffix(string)
if suf_len != 0:
suffix = string[-suf_len:]
minus_suf = string[:-suf_len]
# Check whether we've hit a special-case
if minus_suf and (self._specials.get(hash_string(minus_suf)) != NULL):
string = minus_suf
suffixes.push_back(self.vocab.get(mem, suffix))
has_special[0] = 1
break
if pre_len and suf_len and (pre_len + suf_len) <= len(string):
string = string[pre_len:-suf_len]
prefixes.push_back(self.vocab.get(mem, prefix))
suffixes.push_back(self.vocab.get(mem, suffix))
elif pre_len:
string = minus_pre
prefixes.push_back(self.vocab.get(mem, prefix))
elif suf_len:
string = minus_suf
suffixes.push_back(self.vocab.get(mem, suffix))
if string and (self._specials.get(hash_string(string)) != NULL):
has_special[0] = 1
break
return string
cdef int _attach_tokens(self, Doc tokens, unicode string,
vector[const LexemeC*] *prefixes,
vector[const LexemeC*] *suffixes) except -1:
cdef bint cache_hit
cdef int split, end
cdef const LexemeC* const* lexemes
cdef const LexemeC* lexeme
cdef unicode span
cdef int i
if prefixes.size():
for i in range(prefixes.size()):
tokens.push_back(prefixes[0][i], False)
if string:
cache_hit = self._try_cache(hash_string(string), tokens)
if cache_hit:
pass
elif self.token_match and self.token_match(string):
# We're always saying 'no' to spaces here -- the caller will
# fix up the outermost one, with reference to the original.
# See Issue #859
tokens.push_back(self.vocab.get(tokens.mem, string), False)
else:
matches = self.find_infix(string)
if not matches:
tokens.push_back(self.vocab.get(tokens.mem, string), False)
else:
# let's say we have dyn-o-mite-dave - the regex finds the
# start and end positions of the hyphens
start = 0
start_before_infixes = start
for match in matches:
infix_start = match.start()
infix_end = match.end()
if infix_start == start_before_infixes:
continue
if infix_start != start:
span = string[start:infix_start]
tokens.push_back(self.vocab.get(tokens.mem, span), False)
if infix_start != infix_end:
# If infix_start != infix_end, it means the infix
# token is non-empty. Empty infix tokens are useful
# for tokenization in some languages (see
# https://github.com/explosion/spaCy/issues/768)
infix_span = string[infix_start:infix_end]
tokens.push_back(self.vocab.get(tokens.mem, infix_span), False)
start = infix_end
span = string[start:]
if span:
tokens.push_back(self.vocab.get(tokens.mem, span), False)
cdef vector[const LexemeC*].reverse_iterator it = suffixes.rbegin()
while it != suffixes.rend():
lexeme = deref(it)
preinc(it)
tokens.push_back(lexeme, False)
cdef int _save_cached(self, const TokenC* tokens, hash_t key,
int has_special, int n) except -1:
cdef int i
for i in range(n):
if self.vocab._by_orth.get(tokens[i].lex.orth) == NULL:
return 0
# See https://github.com/explosion/spaCy/issues/1250
if has_special:
return 0
cached = <_Cached*>self.mem.alloc(1, sizeof(_Cached))
cached.length = n
cached.is_lex = True
lexemes = <const LexemeC**>self.mem.alloc(n, sizeof(LexemeC**))
for i in range(n):
lexemes[i] = tokens[i].lex
cached.data.lexemes = <const LexemeC* const*>lexemes
self._cache.set(key, cached)
def find_infix(self, unicode string):
"""Find internal split points of the string, such as hyphens.
string (unicode): The string to segment.
RETURNS (list): A list of `re.MatchObject` objects that have `.start()`
and `.end()` methods, denoting the placement of internal segment
separators, e.g. hyphens.
"""
if self.infix_finditer is None:
return 0
return list(self.infix_finditer(string))
def find_prefix(self, unicode string):
"""Find the length of a prefix that should be segmented from the
string, or None if no prefix rules match.
string (unicode): The string to segment.
RETURNS (int): The length of the prefix if present, otherwise `None`.
"""
if self.prefix_search is None:
return 0
match = self.prefix_search(string)
return (match.end() - match.start()) if match is not None else 0
def find_suffix(self, unicode string):
"""Find the length of a suffix that should be segmented from the
string, or None if no suffix rules match.
string (unicode): The string to segment.
Returns (int): The length of the suffix if present, otherwise `None`.
"""
if self.suffix_search is None:
return 0
match = self.suffix_search(string)
return (match.end() - match.start()) if match is not None else 0
def _load_special_tokenization(self, special_cases):
"""Add special-case tokenization rules."""
for chunk, substrings in sorted(special_cases.items()):
self.add_special_case(chunk, substrings)
def add_special_case(self, unicode string, substrings):
"""Add a special-case tokenization rule.
string (unicode): The string to specially tokenize.
token_attrs (iterable): A sequence of dicts, where each dict describes
a token and its attributes. The `ORTH` fields of the attributes
must exactly match the string when they are concatenated.
"""
substrings = list(substrings)
cached = <_Cached*>self.mem.alloc(1, sizeof(_Cached))
cached.length = len(substrings)
cached.is_lex = False
cached.data.tokens = self.vocab.make_fused_token(substrings)
key = hash_string(string)
self._specials.set(key, cached)
self._cache.set(key, cached)
self._rules[string] = substrings
def to_disk(self, path, **exclude):
"""Save the current state to a directory.
path (unicode or Path): A path to a directory, which will be created if
it doesn't exist. Paths may be either strings or Path-like objects.
"""
with path.open('wb') as file_:
file_.write(self.to_bytes(**exclude))
def from_disk(self, path, **exclude):
"""Loads state from a directory. Modifies the object in place and
returns it.
path (unicode or Path): A path to a directory. Paths may be either
strings or `Path`-like objects.
RETURNS (Tokenizer): The modified `Tokenizer` object.
"""
with path.open('rb') as file_:
bytes_data = file_.read()
self.from_bytes(bytes_data, **exclude)
return self
def to_bytes(self, **exclude):
"""Serialize the current state to a binary string.
**exclude: Named attributes to prevent from being serialized.
RETURNS (bytes): The serialized form of the `Tokenizer` object.
"""
serializers = OrderedDict((
('vocab', lambda: self.vocab.to_bytes()),
('prefix_search', lambda: _get_regex_pattern(self.prefix_search)),
('suffix_search', lambda: _get_regex_pattern(self.suffix_search)),
('infix_finditer', lambda: _get_regex_pattern(self.infix_finditer)),
('token_match', lambda: _get_regex_pattern(self.token_match)),
('exceptions', lambda: OrderedDict(sorted(self._rules.items())))
))
return util.to_bytes(serializers, exclude)
def from_bytes(self, bytes_data, **exclude):
"""Load state from a binary string.
bytes_data (bytes): The data to load from.
**exclude: Named attributes to prevent from being loaded.
RETURNS (Tokenizer): The `Tokenizer` object.
"""
data = OrderedDict()
deserializers = OrderedDict((
('vocab', lambda b: self.vocab.from_bytes(b)),
('prefix_search', lambda b: data.setdefault('prefix_search', b)),
('suffix_search', lambda b: data.setdefault('suffix_search', b)),
('infix_finditer', lambda b: data.setdefault('infix_finditer', b)),
('token_match', lambda b: data.setdefault('token_match', b)),
('exceptions', lambda b: data.setdefault('rules', b))
))
msg = util.from_bytes(bytes_data, deserializers, exclude)
if data.get('prefix_search'):
self.prefix_search = re.compile(data['prefix_search']).search
if data.get('suffix_search'):
self.suffix_search = re.compile(data['suffix_search']).search
if data.get('infix_finditer'):
self.infix_finditer = re.compile(data['infix_finditer']).finditer
if data.get('token_match'):
self.token_match = re.compile(data['token_match']).search
for string, substrings in data.get('rules', {}).items():
self.add_special_case(string, substrings)
return self
def _get_regex_pattern(regex):
"""Get a pattern string for a regex, or None if the pattern is None."""
return None if regex is None else regex.__self__.pattern
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