spaCy - Token.set_extension Classmethod

This class method was introduced in version 2.0. It defines a custom attribute on the Token. Once done, that attribute will become available via Token._.

Arguments

The table below explains its arguments −

NAME	TYPE	DESCRIPTION
name	Unicode	This argument represents the name of the attribute to set by the extension. For example, ‘his_attr’ will be available as doc._.his_attr.
default	-	It is the optional default value of the attribute for the case when no getter or method is defined.
method	callable	It is used to set a custom method on the object. For example, token._.compare(other_token).
getter	callable	This attribute represents the getter function that will takes the object and will return an attribute value. It is mainly called when the user accesses the ._ attribute.
setter	callable	This attribute represents the Setter function that will take the Doc & a value and will modify the object. It is mainly called when the user writes to the Token._ attribute.
Force	bool	It will forcefully overwrite an existing attribute.

Example 1

An example of Token.set_extension class method is as follows −

import spacy
nlp_model = spacy.load("en_core_web_sm")
from spacy.tokens import Token
fruit_getter = lambda token: token.text in ("apple", "pear", "banana")
Token.set_extension("is_fruit", getter=fruit_getter, force=True)
doc = nlp_model("I have an pear")
doc[3]._.is_fruit

Output

True

Example 2

An another example of Token.set_extension class method is as follows −

import spacy
nlp_model = spacy.load("en_core_web_sm")
from spacy.tokens import Token
fruit_getter = lambda token: token.text in ("apple", "pear", "banana")
Token.set_extension("is_fruit", getter=fruit_getter, force=True)
doc = nlp_model("I have a car")
doc[3]._.is_fruit

Output

The output is mentioned below −

False

spacy_container_token_class.htm