//- 💫 DOCS > API > TOKENIZER

include ../../_includes/_mixins

p
    |  Segment text, and create #[code Doc] objects with the discovered segment
    |  boundaries.

+h(2, "init") Tokenizer.__init__
    +tag method

p Create a #[code Tokenizer], to create #[code Doc] objects given unicode text.

+aside-code("Example").
    # Construction 1
    from spacy.tokenizer import Tokenizer
    tokenizer = Tokenizer(nlp.vocab)

    # Construction 2
    from spacy.lang.en import English
    tokenizer = English().Defaults.create_tokenizer(nlp)

+table(["Name", "Type", "Description"])
    +row
        +cell #[code vocab]
        +cell #[code Vocab]
        +cell A storage container for lexical types.

    +row
        +cell #[code rules]
        +cell dict
        +cell Exceptions and special-cases for the tokenizer.

    +row
        +cell #[code prefix_search]
        +cell callable
        +cell
            |  A function matching the signature of
            |  #[code re.compile(string).search] to match prefixes.

    +row
        +cell #[code suffix_search]
        +cell callable
        +cell
            |  A function matching the signature of
            |  #[code re.compile(string).search] to match suffixes.

    +row
        +cell #[code infix_finditer]
        +cell callable
        +cell
            |  A function matching the signature of
            |  #[code re.compile(string).finditer] to find infixes.

    +row
        +cell #[code token_match]
        +cell callable
        +cell A boolean function matching strings to be recognised as tokens.

    +footrow
        +cell returns
        +cell #[code Tokenizer]
        +cell The newly constructed object.

+h(2, "call") Tokenizer.__call__
    +tag method

p Tokenize a string.

+aside-code("Example").
    tokens = tokenizer(u'This is a sentence')
    assert len(tokens) == 4

+table(["Name", "Type", "Description"])
    +row
        +cell #[code string]
        +cell unicode
        +cell The string to tokenize.

    +footrow
        +cell returns
        +cell #[code Doc]
        +cell A container for linguistic annotations.

+h(2, "pipe") Tokenizer.pipe
    +tag method

p Tokenize a stream of texts.

+aside-code("Example").
    texts = [u'One document.', u'...', u'Lots of documents']
    for doc in tokenizer.pipe(texts, batch_size=50):
        pass

+table(["Name", "Type", "Description"])
    +row
        +cell #[code texts]
        +cell -
        +cell A sequence of unicode texts.

    +row
        +cell #[code batch_size]
        +cell int
        +cell The number of texts to accumulate in an internal buffer.

    +row
        +cell #[code n_threads]
        +cell int
        +cell
            |  The number of threads to use, if the implementation supports
            |  multi-threading. The default tokenizer is single-threaded.

    +footrow
        +cell yields
        +cell #[code Doc]
        +cell A sequence of Doc objects, in order.

+h(2, "find_infix") Tokenizer.find_infix
    +tag method

p Find internal split points of the string.

+table(["Name", "Type", "Description"])
    +row
        +cell #[code string]
        +cell unicode
        +cell The string to split.

    +footrow
        +cell returns
        +cell list
        +cell
            |  A list of #[code re.MatchObject] objects that have #[code .start()]
            |  and #[code .end()] methods, denoting the placement of internal
            |  segment separators, e.g. hyphens.

+h(2, "find_prefix") Tokenizer.find_prefix
    +tag method

p
    |  Find the length of a prefix that should be segmented from the string, or
    |  #[code None] if no prefix rules match.

+table(["Name", "Type", "Description"])
    +row
        +cell #[code string]
        +cell unicode
        +cell The string to segment.

    +footrow
        +cell returns
        +cell int
        +cell The length of the prefix if present, otherwise #[code None].

+h(2, "find_suffix") Tokenizer.find_suffix
    +tag method

p
    |  Find the length of a suffix that should be segmented from the string, or
    |  #[code None] if no suffix rules match.

+table(["Name", "Type", "Description"])
    +row
        +cell #[code string]
        +cell unicode
        +cell The string to segment.

    +footrow
        +cell returns
        +cell int / #[code None]
        +cell The length of the suffix if present, otherwise #[code None].

+h(2, "add_special_case") Tokenizer.add_special_case
    +tag method

p
    |  Add a special-case tokenization rule. This mechanism is also used to add
    |  custom tokenizer exceptions to the language data. See the usage workflow
    |  on #[+a("/docs/usage/adding-languages#tokenizer-exceptions") adding languages]
    |  for more details and examples.

+aside-code("Example").
    from spacy.attrs import ORTH, LEMMA
    case = [{"don't": [{ORTH: "do"}, {ORTH: "n't", LEMMA: "not"}]}]
    tokenizer.add_special_case(case)

+table(["Name", "Type", "Description"])
    +row
        +cell #[code string]
        +cell unicode
        +cell The string to specially tokenize.

    +row
        +cell #[code token_attrs]
        +cell iterable
        +cell
            |  A sequence of dicts, where each dict describes a token and its
            |  attributes. The #[code ORTH] fields of the attributes must
            |  exactly match the string when they are concatenated.

+h(2, "attributes") Attributes

+table(["Name", "Type", "Description"])
    +row
        +cell #[code vocab]
        +cell #[code Vocab]
        +cell The vocab object of the parent #[code Doc].

    +row
        +cell #[code prefix_search]
        +cell -
        +cell
            |  A function to find segment boundaries from the start of a
            |  string. Returns the length of the segment, or #[code None].

    +row
        +cell #[code suffix_search]
        +cell -
        +cell
            |  A function to find segment boundaries from the end of a string.
            |  Returns the length of the segment, or #[code None].

    +row
        +cell #[code infix_finditer]
        +cell -
        +cell
            |  A function to find internal segment separators, e.g. hyphens.
            |  Returns a (possibly empty) list of #[code re.MatchObject]
            |  objects.