spaCy/website/docs/api/token.md
Tclack88 ab8dc2732c Update token.md (#4767)
* Update token.md

documentation is confusing: A '?' is a right punct, but '¿' is a left punct

* Update token.md

add quotations around parentheses in `is_left_punct` and `is_right_punct` for clarrification, ensuring the question mark that follows is not percieved as an example of left and right punctuation

* Move quotes into code block [ci skip]
2019-12-06 19:22:02 +01:00

35 KiB

title teaser tag source
Token An individual token — i.e. a word, punctuation symbol, whitespace, etc. class spacy/tokens/token.pyx

Token.__init__

Construct a Token object.

Example

doc = nlp("Give it back! He pleaded.")
token = doc[0]
assert token.text == "Give"
Name Type Description
vocab Vocab A storage container for lexical types.
doc Doc The parent document.
offset int The index of the token within the document.
RETURNS Token The newly constructed object.

Token.__len__

The number of unicode characters in the token, i.e. token.text.

Example

doc = nlp("Give it back! He pleaded.")
token = doc[0]
assert len(token) == 4
Name Type Description
RETURNS int The number of unicode characters in the token.

Token.set_extension

Define a custom attribute on the Token which becomes available via Token._. For details, see the documentation on custom attributes.

Example

from spacy.tokens import Token
fruit_getter = lambda token: token.text in ("apple", "pear", "banana")
Token.set_extension("is_fruit", getter=fruit_getter)
doc = nlp("I have an apple")
assert doc[3]._.is_fruit
Name Type Description
name unicode Name of the attribute to set by the extension. For example, 'my_attr' will be available as token._.my_attr.
default - Optional default value of the attribute if no getter or method is defined.
method callable Set a custom method on the object, for example token._.compare(other_token).
getter callable Getter function that takes the object and returns an attribute value. Is called when the user accesses the ._ attribute.
setter callable Setter function that takes the Token and a value, and modifies the object. Is called when the user writes to the Token._ attribute.
force bool Force overwriting existing attribute.

Token.get_extension

Look up a previously registered extension by name. Returns a 4-tuple (default, method, getter, setter) if the extension is registered. Raises a KeyError otherwise.

Example

from spacy.tokens import Token
Token.set_extension("is_fruit", default=False)
extension = Token.get_extension("is_fruit")
assert extension == (False, None, None, None)
Name Type Description
name unicode Name of the extension.
RETURNS tuple A (default, method, getter, setter) tuple of the extension.

Token.has_extension

Check whether an extension has been registered on the Token class.

Example

from spacy.tokens import Token
Token.set_extension("is_fruit", default=False)
assert Token.has_extension("is_fruit")
Name Type Description
name unicode Name of the extension to check.
RETURNS bool Whether the extension has been registered.

Token.remove_extension {#remove_extension tag="classmethod" new=""2.0.11""}

Remove a previously registered extension.

Example

from spacy.tokens import Token
Token.set_extension("is_fruit", default=False)
removed = Token.remove_extension("is_fruit")
assert not Token.has_extension("is_fruit")
Name Type Description
name unicode Name of the extension.
RETURNS tuple A (default, method, getter, setter) tuple of the removed extension.

Token.check_flag

Check the value of a boolean flag.

Example

from spacy.attrs import IS_TITLE
doc = nlp("Give it back! He pleaded.")
token = doc[0]
assert token.check_flag(IS_TITLE) == True
Name Type Description
flag_id int The attribute ID of the flag to check.
RETURNS bool Whether the flag is set.

Token.similarity

Compute a semantic similarity estimate. Defaults to cosine over vectors.

Example

apples, _, oranges = nlp("apples and oranges")
apples_oranges = apples.similarity(oranges)
oranges_apples = oranges.similarity(apples)
assert apples_oranges == oranges_apples
Name Type Description
other - The object to compare with. By default, accepts Doc, Span, Token and Lexeme objects.
RETURNS float A scalar similarity score. Higher is more similar.

Token.nbor

Get a neighboring token.

Example

doc = nlp("Give it back! He pleaded.")
give_nbor = doc[0].nbor()
assert give_nbor.text == "it"
Name Type Description
i int The relative position of the token to get. Defaults to 1.
RETURNS Token The token at position self.doc[self.i+i].

Token.is_ancestor

Check whether this token is a parent, grandparent, etc. of another in the dependency tree.

Example

doc = nlp("Give it back! He pleaded.")
give = doc[0]
it = doc[1]
assert give.is_ancestor(it)
Name Type Description
descendant Token Another token.
RETURNS bool Whether this token is the ancestor of the descendant.

Token.ancestors

The rightmost token of this token's syntactic descendants.

Example

doc = nlp("Give it back! He pleaded.")
it_ancestors = doc[1].ancestors
assert [t.text for t in it_ancestors] == ["Give"]
he_ancestors = doc[4].ancestors
assert [t.text for t in he_ancestors] == ["pleaded"]
Name Type Description
YIELDS Token A sequence of ancestor tokens such that ancestor.is_ancestor(self).

Token.conjuncts

A tuple of coordinated tokens, not including the token itself.

Example

doc = nlp("I like apples and oranges")
apples_conjuncts = doc[2].conjuncts
assert [t.text for t in apples_conjuncts] == ["oranges"]
Name Type Description
RETURNS tuple The coordinated tokens.

Token.children

A sequence of the token's immediate syntactic children.

Example

doc = nlp("Give it back! He pleaded.")
give_children = doc[0].children
assert [t.text for t in give_children] == ["it", "back", "!"]
Name Type Description
YIELDS Token A child token such that child.head==self.

Token.lefts

The leftward immediate children of the word, in the syntactic dependency parse.

Example

doc = nlp("I like New York in Autumn.")
lefts = [t.text for t in doc[3].lefts]
assert lefts == ["New"]
Name Type Description
YIELDS Token A left-child of the token.

Token.rights

The rightward immediate children of the word, in the syntactic dependency parse.

Example

doc = nlp("I like New York in Autumn.")
rights = [t.text for t in doc[3].rights]
assert rights == ["in"]
Name Type Description
YIELDS Token A right-child of the token.

Token.n_lefts

The number of leftward immediate children of the word, in the syntactic dependency parse.

Example

doc = nlp("I like New York in Autumn.")
assert doc[3].n_lefts == 1
Name Type Description
RETURNS int The number of left-child tokens.

Token.n_rights

The number of rightward immediate children of the word, in the syntactic dependency parse.

Example

doc = nlp("I like New York in Autumn.")
assert doc[3].n_rights == 1
Name Type Description
RETURNS int The number of right-child tokens.

Token.subtree

A sequence containing the token and all the token's syntactic descendants.

Example

doc = nlp("Give it back! He pleaded.")
give_subtree = doc[0].subtree
assert [t.text for t in give_subtree] == ["Give", "it", "back", "!"]
Name Type Description
YIELDS Token A descendant token such that self.is_ancestor(token) or token == self.

Token.is_sent_start

A boolean value indicating whether the token starts a sentence. None if unknown. Defaults to True for the first token in the Doc.

Example

doc = nlp("Give it back! He pleaded.")
assert doc[4].is_sent_start
assert not doc[5].is_sent_start
Name Type Description
RETURNS bool Whether the token starts a sentence.

As of spaCy v2.0, the Token.sent_start property is deprecated and has been replaced with Token.is_sent_start, which returns a boolean value instead of a misleading 0 for False and 1 for True. It also now returns None if the answer is unknown, and fixes a quirk in the old logic that would always set the property to 0 for the first word of the document.

- assert doc[4].sent_start == 1
+ assert doc[4].is_sent_start == True

Token.has_vector

A boolean value indicating whether a word vector is associated with the token.

Example

doc = nlp("I like apples")
apples = doc[2]
assert apples.has_vector
Name Type Description
RETURNS bool Whether the token has a vector data attached.

Token.vector

A real-valued meaning representation.

Example

doc = nlp("I like apples")
apples = doc[2]
assert apples.vector.dtype == "float32"
assert apples.vector.shape == (300,)
Name Type Description
RETURNS numpy.ndarray[ndim=1, dtype='float32'] A 1D numpy array representing the token's semantics.

Token.vector_norm

The L2 norm of the token's vector representation.

Example

doc = nlp("I like apples and pasta")
apples = doc[2]
pasta = doc[4]
apples.vector_norm  # 6.89589786529541
pasta.vector_norm  # 7.759851932525635
assert apples.vector_norm != pasta.vector_norm
Name Type Description
RETURNS float The L2 norm of the vector representation.

Attributes

Name Type Description
doc Doc The parent document.
sent 2.0.12 Span The sentence span that this token is a part of.
text unicode Verbatim text content.
text_with_ws unicode Text content, with trailing space character if present.
whitespace_ unicode Trailing space character if present.
orth int ID of the verbatim text content.
orth_ unicode Verbatim text content (identical to Token.text). Exists mostly for consistency with the other attributes.
vocab Vocab The vocab object of the parent Doc.
tensor 2.1.7 ndarray The tokens's slice of the parent Doc's tensor.
head Token The syntactic parent, or "governor", of this token.
left_edge Token The leftmost token of this token's syntactic descendants.
right_edge Token The rightmost token of this token's syntactic descendants.
i int The index of the token within the parent document.
ent_type int Named entity type.
ent_type_ unicode Named entity type.
ent_iob int IOB code of named entity tag. 3 means the token begins an entity, 2 means it is outside an entity, 1 means it is inside an entity, and 0 means no entity tag is set.
ent_iob_ unicode IOB code of named entity tag. "B" means the token begins an entity, "I" means it is inside an entity, "O" means it is outside an entity, and "" means no entity tag is set.
ent_kb_id 2.2 int Knowledge base ID that refers to the named entity this token is a part of, if any.
ent_kb_id_ 2.2 unicode Knowledge base ID that refers to the named entity this token is a part of, if any.
ent_id int ID of the entity the token is an instance of, if any. Currently not used, but potentially for coreference resolution.
ent_id_ unicode ID of the entity the token is an instance of, if any. Currently not used, but potentially for coreference resolution.
lemma int Base form of the token, with no inflectional suffixes.
lemma_ unicode Base form of the token, with no inflectional suffixes.
norm int The token's norm, i.e. a normalized form of the token text. Usually set in the language's tokenizer exceptions or norm exceptions.
norm_ unicode The token's norm, i.e. a normalized form of the token text. Usually set in the language's tokenizer exceptions or norm exceptions.
lower int Lowercase form of the token.
lower_ unicode Lowercase form of the token text. Equivalent to Token.text.lower().
shape int Transform of the tokens's string, to show orthographic features. Alphabetic characters are replaced by x or X, and numeric characters are replaced by d, and sequences of the same character are truncated after length 4. For example,"Xxxx"or"dd"`.
shape_ unicode Transform of the tokens's string, to show orthographic features. Alphabetic characters are replaced by x or X, and numeric characters are replaced by d, and sequences of the same character are truncated after length 4. For example,"Xxxx"or"dd"`.
prefix int Hash value of a length-N substring from the start of the token. Defaults to N=1.
prefix_ unicode A length-N substring from the start of the token. Defaults to N=1.
suffix int Hash value of a length-N substring from the end of the token. Defaults to N=3.
suffix_ unicode Length-N substring from the end of the token. Defaults to N=3.
is_alpha bool Does the token consist of alphabetic characters? Equivalent to token.text.isalpha().
is_ascii bool Does the token consist of ASCII characters? Equivalent to all(ord(c) < 128 for c in token.text).
is_digit bool Does the token consist of digits? Equivalent to token.text.isdigit().
is_lower bool Is the token in lowercase? Equivalent to token.text.islower().
is_upper bool Is the token in uppercase? Equivalent to token.text.isupper().
is_title bool Is the token in titlecase? Equivalent to token.text.istitle().
is_punct bool Is the token punctuation?
is_left_punct bool Is the token a left punctuation mark, e.g. '(' ?
is_right_punct bool Is the token a right punctuation mark, e.g. ')' ?
is_space bool Does the token consist of whitespace characters? Equivalent to token.text.isspace().
is_bracket bool Is the token a bracket?
is_quote bool Is the token a quotation mark?
is_currency 2.0.8 bool Is the token a currency symbol?
like_url bool Does the token resemble a URL?
like_num bool Does the token represent a number? e.g. "10.9", "10", "ten", etc.
like_email bool Does the token resemble an email address?
is_oov bool Is the token out-of-vocabulary?
is_stop bool Is the token part of a "stop list"?
pos int Coarse-grained part-of-speech.
pos_ unicode Coarse-grained part-of-speech.
tag int Fine-grained part-of-speech.
tag_ unicode Fine-grained part-of-speech.
dep int Syntactic dependency relation.
dep_ unicode Syntactic dependency relation.
lang int Language of the parent document's vocabulary.
lang_ unicode Language of the parent document's vocabulary.
prob float Smoothed log probability estimate of token's word type (context-independent entry in the vocabulary).
idx int The character offset of the token within the parent document.
sentiment float A scalar value indicating the positivity or negativity of the token.
lex_id int Sequential ID of the token's lexical type, used to index into tables, e.g. for word vectors.
rank int Sequential ID of the token's lexical type, used to index into tables, e.g. for word vectors.
cluster int Brown cluster ID.
_ Underscore User space for adding custom attribute extensions.