# 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 regex as 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 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_hash.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 = self.mem.alloc(n, sizeof(LexemeC**)) for i in range(n): lexemes[i] = tokens[i].lex cached.data.lexemes = 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: self.prefix_search.__self__.pattern), ('suffix_search', lambda: self.suffix_search.__self__.pattern), ('infix_finditer', lambda: self.infix_finditer.__self__.pattern), ('token_match', lambda: self.token_match.__self__.pattern), ('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 'prefix_search' in data: self.prefix_search = re.compile(data['prefix_search']).search if 'suffix_search' in data: self.suffix_search = re.compile(data['suffix_search']).search if 'infix_finditer' in data: self.infix_finditer = re.compile(data['infix_finditer']).finditer if 'token_match' in data: 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