spaCy/website/docs/api/language.md

title	teaser	tag	source
Language	A text-processing pipeline	class	spacy/language.py

Usually you'll load this once per process as nlp and pass the instance around your application. The Language class is created when you call spacy.load() and contains the shared vocabulary and language data, optional model data loaded from a model package or a path, and a processing pipeline containing components like the tagger or parser that are called on a document in order. You can also add your own processing pipeline components that take a Doc object, modify it and return it.

Language.__init__

Initialize a Language object.

Example

# Construction from subclass
from spacy.lang.en import English
nlp = English()

# Construction from scratch
from spacy.vocab import Vocab
from spacy.language import Language
nlp = Language(Vocab())

Name	Type	Description
vocab	Vocab	A Vocab object. If True, a vocab is created using the default language data settings.
keyword-only
max_length	int	Maximum number of characters allowed in a single text. Defaults to 10 ** 6.
meta	dict	Custom meta data for the Language class. Is written to by models to add model meta data.
create_tokenizer	Callable	Optional function that receives the nlp object and returns a tokenizer.

Language.from_config

Create a Language object from a loaded config. Will set up the tokenizer and language data, add pipeline components based on the pipeline and components define in the config and validate the results. If no config is provided, the default config of the given language is used. This is also how spaCy loads a model under the hood based on its config.cfg.

Example

from thinc.api import Config
from spacy.language import Language

config = Config().from_disk("./config.cfg")
nlp = Language.from_config(config)

Name	Type	Description
config	Dict[str, Any] / Config	The loaded config.
keyword-only
disable	Iterable[str]	List of pipeline component names to disable.
auto_fill	bool	Whether to automatically fill in missing values in the config, based on defaults and function argument annotations. Defaults to True.
validate	bool	Whether to validate the component config and arguments against the types expected by the factory. Defaults to True.
RETURNS	Language	The initialized object.

Language.component

Register a custom pipeline component under a given name. This allows initializing the component by name using Language.add_pipe and referring to it in config files. This classmethod and decorator is intended for simple stateless functions that take a Doc and return it. For more complex stateful components that allow settings and need access to the shared nlp object, use the Language.factory decorator. For more details and examples, see the usage documentation.

Example

from spacy.language import Language

# Usage as a decorator
@Language.component("my_component")
def my_component(doc):
   # Do something to the doc
   return doc

# Usage as a function
Language.component("my_component2", func=my_component)

Name	Type	Description
name	str	The name of the component factory.
keyword-only
assigns	Iterable[str]	Doc or Token attributes assigned by this component, e.g. ["token.ent_id"]. Used for pipeline analysis.
requires	Iterable[str]	Doc or Token attributes required by this component, e.g. ["token.ent_id"]. Used for pipeline analysis.
retokenizes	bool	Whether the component changes tokenization. Used for pipeline analysis.
scores	Iterable[str]	All scores set by the components if it's trainable, e.g. ["ents_f", "ents_r", "ents_p"].
default_score_weights	Dict[str, float]	The scores to report during training, and their default weight towards the final score used to select the best model. Weights should sum to 1.0 per component and will be combined and normalized for the whole pipeline.
func	Optional[Callable]	Optional function if not used a a decorator.

Language.factory

Register a custom pipeline component factory under a given name. This allows initializing the component by name using Language.add_pipe and referring to it in config files. The registered factory function needs to take at least two named arguments which spaCy fills in automatically: nlp for the current nlp object and name for the component instance name. This can be useful to distinguish multiple instances of the same component and allows trainable components to add custom losses using the component instance name. The default_config defines the default values of the remaining factory arguments. It's merged into the nlp.config. For more details and examples, see the usage documentation.

Example

from spacy.language import Language

# Usage as a decorator
@Language.factory(
   "my_component",
   default_config={"some_setting": True},
)
def create_my_component(nlp, name, some_setting):
     return MyComponent(some_setting)

# Usage as function
Language.factory(
    "my_component",
    default_config={"some_setting": True},
    func=create_my_component
)

Name	Type	Description
name	str	The name of the component factory.
keyword-only
default_config	Dict[str, any]	The default config, describing the default values of the factory arguments.
assigns	Iterable[str]	Doc or Token attributes assigned by this component, e.g. ["token.ent_id"]. Used for pipeline analysis.
requires	Iterable[str]	Doc or Token attributes required by this component, e.g. ["token.ent_id"]. Used for pipeline analysis.
retokenizes	bool	Whether the component changes tokenization. Used for pipeline analysis.
scores	Iterable[str]	All scores set by the components if it's trainable, e.g. ["ents_f", "ents_r", "ents_p"].
default_score_weights	Dict[str, float]	The scores to report during training, and their default weight towards the final score used to select the best model. Weights should sum to 1.0 per component and will be combined and normalized for the whole pipeline.
func	Optional[Callable]	Optional function if not used a a decorator.

Language.__call__

Apply the pipeline to some text. The text can span multiple sentences, and can contain arbitrary whitespace. Alignment into the original string is preserved.

Example

doc = nlp("An example sentence. Another sentence.")
assert (doc[0].text, doc[0].head.tag_) == ("An", "NN")

Name	Type	Description
text	str	The text to be processed.
keyword-only
disable	List[str]	Names of pipeline components to disable.
component_cfg	Dict[str, dict]	Optional dictionary of keyword arguments for components, keyed by component names. Defaults to None.
RETURNS	Doc	A container for accessing the annotations.

Language.pipe

Process texts as a stream, and yield Doc objects in order. This is usually more efficient than processing texts one-by-one.

Example

texts = ["One document.", "...", "Lots of documents"]
for doc in nlp.pipe(texts, batch_size=50):
    assert doc.is_parsed

Name	Type	Description
texts	Iterable[str]	A sequence of strings.
keyword-only
as_tuples	bool	If set to True, inputs should be a sequence of (text, context) tuples. Output will then be a sequence of (doc, context) tuples. Defaults to False.
batch_size	int	The number of texts to buffer.
disable	List[str]	Names of pipeline components to disable.
cleanup	bool	If True, unneeded strings are freed to control memory use. Experimental.
component_cfg	Dict[str, dict]	Optional dictionary of keyword arguments for components, keyed by component names. Defaults to None.
n_process 2.2.2	int	Number of processors to use, only supported in Python 3. Defaults to 1.
YIELDS	Doc	Documents in the order of the original text.

Language.begin_training

Initialize the pipe for training, using data examples if available. Returns an Optimizer object.

Example

optimizer = nlp.begin_training(get_examples)

Name	Type	Description
get_examples	Callable[[], Iterable[Example]]	Optional function that returns gold-standard annotations in the form of Example objects.
keyword-only
sgd	Optimizer	An optional optimizer. Will be created via create_optimizer if not set.
RETURNS	Optimizer	The optimizer.

Language.resume_training

Continue training a pretrained model. Create and return an optimizer, and initialize "rehearsal" for any pipeline component that has a rehearse method. Rehearsal is used to prevent models from "forgetting" their initialized "knowledge". To perform rehearsal, collect samples of text you want the models to retain performance on, and call nlp.rehearse with a batch of Example objects.

Example

optimizer = nlp.resume_training()
nlp.rehearse(examples, sgd=optimizer)

Name	Type	Description
keyword-only
sgd	Optimizer	An optional optimizer. Will be created via create_optimizer if not set.
RETURNS	Optimizer	The optimizer.

Language.update

Update the models in the pipeline.

Example

for raw_text, entity_offsets in train_data:
    doc = nlp.make_doc(raw_text)
    example = Example.from_dict(doc, {"entities": entity_offsets})
    nlp.update([example], sgd=optimizer)

Name	Type	Description
examples	Iterable[Example]	A batch of Example objects to learn from.
keyword-only
drop	float	The dropout rate.
sgd	Optimizer	The optimizer.
losses	Dict[str, float]	Dictionary to update with the loss, keyed by pipeline component.
component_cfg	Dict[str, dict]	Optional dictionary of keyword arguments for components, keyed by component names. Defaults to None.
RETURNS	Dict[str, float]	The updated losses dictionary.

Language.rehearse

Perform a "rehearsal" update from a batch of data. Rehearsal updates teach the current model to make predictions similar to an initial model, to try to address the "catastrophic forgetting" problem. This feature is experimental.

Example

optimizer = nlp.resume_training()
losses = nlp.rehearse(examples, sgd=optimizer)

Name	Type	Description
examples	Iterable[Example]	A batch of Example objects to learn from.
keyword-only
drop	float	The dropout rate.
sgd	Optimizer	The optimizer.
losses	Dict[str, float]	Optional record of the loss during training. Updated using the component name as the key.
RETURNS	Dict[str, float]	The updated losses dictionary.

Language.evaluate

Evaluate a model's pipeline components.

Example

scores = nlp.evaluate(examples, verbose=True)
print(scores)

Name	Type	Description
examples	Iterable[Example]	A batch of Example objects to learn from.
keyword-only
verbose	bool	Print debugging information.
batch_size	int	The batch size to use.
scorer	Scorer	Optional Scorer to use. If not passed in, a new one will be created.
component_cfg	Dict[str, dict]	Optional dictionary of keyword arguments for components, keyed by component names. Defaults to None.
RETURNS	Dict[str, Union[float, dict]]	A dictionary of evaluation scores.

Language.use_params

Replace weights of models in the pipeline with those provided in the params dictionary. Can be used as a context manager, in which case, models go back to their original weights after the block.

Example

with nlp.use_params(optimizer.averages):
    nlp.to_disk("/tmp/checkpoint")

Name	Type	Description
params	dict	A dictionary of parameters keyed by model ID.

Language.create_pipe

Create a pipeline component from a factory.

As of v3.0, the Language.add_pipe method also takes the string name of the factory, creates the component, adds it to the pipeline and returns it. The Language.create_pipe method is now mostly used internally. To create a component and add it to the pipeline, you should always use Language.add_pipe.

Example

parser = nlp.create_pipe("parser")

Name	Type	Description
factory_name	str	Name of the registered component factory.
name	str	Optional unique name of pipeline component instance. If not set, the factory name is used. An error is raised if the name already exists in the pipeline.
keyword-only
config 3	Dict[str, Any]	Optional config parameters to use for this component. Will be merged with the default_config specified by the component factory.
validate 3	bool	Whether to validate the component config and arguments against the types expected by the factory. Defaults to True.
RETURNS	callable	The pipeline component.

Language.add_pipe

Add a component to the processing pipeline. Expects a name that maps to a component factory registered using @Language.component or @Language.factory. Components should be callables that take a Doc object, modify it and return it. Only one of before, after, first or last can be set. Default behavior is last=True.

As of v3.0, the Language.add_pipe method doesn't take callables anymore and instead expects the name of a component factory registered using @Language.component or @Language.factory. It now takes care of creating the component, adds it to the pipeline and returns it.

Example

@Language.component("component")
def component_func(doc):
    # modify Doc and return it return doc

nlp.add_pipe("component", before="ner")
component = nlp.add_pipe("component", name="custom_name", last=True)

Name	Type	Description
factory_name	str	Name of the registered component factory.
name	str	Optional unique name of pipeline component instance. If not set, the factory name is used. An error is raised if the name already exists in the pipeline.
keyword-only
before	str / int	Component name or index to insert component directly before.
after	str / int	Component name or index to insert component directly after:
first	bool	Insert component first / not first in the pipeline.
last	bool	Insert component last / not last in the pipeline.
config 3	Dict[str, Any]	Optional config parameters to use for this component. Will be merged with the default_config specified by the component factory.
validate 3	bool	Whether to validate the component config and arguments against the types expected by the factory. Defaults to True.
RETURNS 3	callable	The pipeline component.

Language.has_factory

Check whether a factory name is registered on the Language class or subclass. Will check for language-specific factories registered on the subclass, as well as general-purpose factories registered on the Language base class, available to all subclasses.

Example

from spacy.language import Language
from spacy.lang.en import English

@English.component("component")
def component(doc):
    return doc

assert English.has_factory("component")
assert not Language.has_factory("component")

Name	Type	Description
name	str	Name of the pipeline factory to check.
RETURNS	bool	Whether a factory of that name is registered on the class.

Language.has_pipe

Check whether a component is present in the pipeline. Equivalent to name in nlp.pipe_names.

Example

@Language.component("component")
def component(doc):
    return doc

nlp.add_pipe("component", name="my_component")
assert "my_component" in nlp.pipe_names
assert nlp.has_pipe("my_component")

Name	Type	Description
name	str	Name of the pipeline component to check.
RETURNS	bool	Whether a component of that name exists in the pipeline.

Language.get_pipe

Get a pipeline component for a given component name.

Example

parser = nlp.get_pipe("parser")
custom_component = nlp.get_pipe("custom_component")

Name	Type	Description
name	str	Name of the pipeline component to get.
RETURNS	callable	The pipeline component.

Language.replace_pipe

Replace a component in the pipeline.

Example

nlp.replace_pipe("parser", my_custom_parser)

Name	Type	Description
name	str	Name of the component to replace.
component	callable	The pipeline component to insert.
keyword-only
config 3	Dict[str, Any]	Optional config parameters to use for the new component. Will be merged with the default_config specified by the component factory.
validate 3	bool	Whether to validate the component config and arguments against the types expected by the factory. Defaults to True.

Language.rename_pipe

Rename a component in the pipeline. Useful to create custom names for pre-defined and pre-loaded components. To change the default name of a component added to the pipeline, you can also use the name argument on add_pipe.

Example

nlp.rename_pipe("parser", "spacy_parser")

Name	Type	Description
old_name	str	Name of the component to rename.
new_name	str	New name of the component.

Language.remove_pipe

Remove a component from the pipeline. Returns the removed component name and component function.

Example

name, component = nlp.remove_pipe("parser")
assert name == "parser"

Name	Type	Description
name	str	Name of the component to remove.
RETURNS	tuple	A (name, component) tuple of the removed component.

Language.select_pipes

Disable one or more pipeline components. If used as a context manager, the pipeline will be restored to the initial state at the end of the block. Otherwise, a DisabledPipes object is returned, that has a .restore() method you can use to undo your changes. You can specify either disable (as a list or string), or enable. In the latter case, all components not in the enable list, will be disabled.

Example

with nlp.select_pipes(disable=["tagger", "parser"]):
   nlp.begin_training()

with nlp.select_pipes(enable="ner"):
    nlp.begin_training()

disabled = nlp.select_pipes(disable=["tagger", "parser"])
nlp.begin_training()
disabled.restore()

As of spaCy v3.0, the disable_pipes method has been renamed to select_pipes:

- nlp.disable_pipes(["tagger", "parser"])
+ nlp.select_pipes(disable=["tagger", "parser"])

Name	Type	Description
keyword-only
disable	str / list	Name(s) of pipeline components to disable.
enable	str / list	Names(s) of pipeline components that will not be disabled.
RETURNS	DisabledPipes	The disabled pipes that can be restored by calling the object's .restore() method.

Language.get_factory_meta

Get the factory meta information for a given pipeline component name. Expects the name of the component factory. The factory meta is an instance of the FactoryMeta dataclass and contains the information about the component and its default provided by the @Language.component or @Language.factory decorator.

Example

factory_meta = Language.get_factory_meta("ner")
assert factory_meta.factory == "ner"
print(factory_meta.default_config)

Name	Type	Description
name	str	The factory name.
RETURNS	FactoryMeta	The factory meta.

Language.get_pipe_meta

Get the factory meta information for a given pipeline component name. Expects the name of the component instance in the pipeline. The factory meta is an instance of the FactoryMeta dataclass and contains the information about the component and its default provided by the @Language.component or @Language.factory decorator.

Example

nlp.add_pipe("ner", name="entity_recognizer")
factory_meta = nlp.get_pipe_meta("entity_recognizer")
assert factory_meta.factory == "ner"
print(factory_meta.default_config)

Name	Type	Description
name	str	The pipeline component name.
RETURNS	FactoryMeta	The factory meta.

Language.meta

Custom meta data for the Language class. If a model is loaded, contains meta data of the model. The Language.meta is also what's serialized as the meta.json when you save an nlp object to disk.

Example

print(nlp.meta)

Name	Type	Description
RETURNS	dict	The meta data.

Language.config

Export a trainable config.cfg for the current nlp object. Includes the current pipeline, all configs used to create the currently active pipeline components, as well as the default training config that can be used with spacy train. Language.config returns a Thinc Config object, which is a subclass of the built-in dict. It supports the additional methods to_disk (serialize the config to a file) and to_str (output the config as a string).

Example

nlp.config.to_disk("./config.cfg")
print(nlp.config.to_str())

Name	Type	Description
RETURNS	Config	The config.

Language.to_disk

Save the current state to a directory. If a model is loaded, this will include the model.

Example

nlp.to_disk("/path/to/models")

Name	Type	Description
path	str / Path	A path to a directory, which will be created if it doesn't exist. Paths may be either strings or Path-like objects.
exclude	list	Names of pipeline components or serialization fields to exclude.

Language.from_disk

Loads state from a directory. Modifies the object in place and returns it. If the saved Language object contains a model, the model will be loaded. Note that this method is commonly used via the subclasses like English or German to make language-specific functionality like the lexical attribute getters available to the loaded object.

Example

from spacy.language import Language
nlp = Language().from_disk("/path/to/model")

# using language-specific subclass
from spacy.lang.en import English
nlp = English().from_disk("/path/to/en_model")

Name	Type	Description
path	str / Path	A path to a directory. Paths may be either strings or Path-like objects.
exclude	list	Names of pipeline components or serialization fields to exclude.
RETURNS	Language	The modified Language object.

Language.to_bytes

Serialize the current state to a binary string.

Example

nlp_bytes = nlp.to_bytes()

Name	Type	Description
exclude	list	Names of pipeline components or serialization fields to exclude.
RETURNS	bytes	The serialized form of the Language object.

Language.from_bytes

Load state from a binary string. Note that this method is commonly used via the subclasses like English or German to make language-specific functionality like the lexical attribute getters available to the loaded object.

Example

from spacy.lang.en import English
nlp_bytes = nlp.to_bytes()
nlp2 = English()
nlp2.from_bytes(nlp_bytes)

Name	Type	Description
bytes_data	bytes	The data to load from.
exclude	list	Names of pipeline components or serialization fields to exclude.
RETURNS	Language	The Language object.

Attributes

Name	Type	Description
vocab	Vocab	A container for the lexical types.
tokenizer	Tokenizer	The tokenizer.
make_doc	Callable	Callable that takes a string and returns a Doc.
pipeline	List[str, Callable]	List of (name, component) tuples describing the current processing pipeline, in order.
pipe_names 2	List[str]	List of pipeline component names, in order.
pipe_labels 2.2	Dict[str, List[str]]	List of labels set by the pipeline components, if available, keyed by component name.
pipe_factories 2.2	Dict[str, str]	Dictionary of pipeline component names, mapped to their factory names.
factories	Dict[str, Callable]	All available factory functions, keyed by name.
factory_names 3	List[str]	List of all available factory names.
path 2	Path	Path to the model data directory, if a model is loaded. Otherwise None.

Class attributes

Name	Type	Description
Defaults	class	Settings, data and factory methods for creating the nlp object and processing pipeline.
lang	str	Two-letter language ID, i.e. ISO code.
default_config	dict	Base config to use for Language.config. Defaults to default_config.cfg.

Defaults

The following attributes can be set on the Language.Defaults class to customize the default language data:

Example

from spacy.language import language
from spacy.lang.tokenizer_exceptions import URL_MATCH
from thinc.api import Config

DEFAULT_CONFIFG = """
[nlp.tokenizer]
@tokenizers = "MyCustomTokenizer.v1"
"""

class Defaults(Language.Defaults):
   stop_words = set()
   tokenizer_exceptions = {}
   prefixes = tuple()
   suffixes = tuple()
   infixes = tuple()
   token_match = None
   url_match = URL_MATCH
   lex_attr_getters = {}
   syntax_iterators = {}
   writing_system = {"direction": "ltr", "has_case": True, "has_letters": True}
   config = Config().from_str(DEFAULT_CONFIG)

Name	Description
stop_words	List of stop words, used for Token.is_stop. Example: stop_words.py
tokenizer_exceptions	Tokenizer exception rules, string mapped to list of token attributes. Example: de/tokenizer_exceptions.py
prefixes, suffixes, infixes	Prefix, suffix and infix rules for the default tokenizer. Example: puncutation.py
token_match	Optional regex for matching strings that should never be split, overriding the infix rules. Example: fr/tokenizer_exceptions.py
url_match	Regular expression for matching URLs. Prefixes and suffixes are removed before applying the match. Example: tokenizer_exceptions.py
lex_attr_getters	Custom functions for setting lexical attributes on tokens, e.g. like_num. Example: lex_attrs.py
syntax_iterators	Functions that compute views of a Doc object based on its syntax. At the moment, only used for noun chunks. Example: syntax_iterators.py.
writing_system	Information about the language's writing system, available via Vocab.writing_system. Defaults to: {"direction": "ltr", "has_case": True, "has_letters": True}.. Example: zh/__init__.py
config	Default config added to nlp.config. This can include references to custom tokenizers or lemmatizers. Example: zh/__init__.py

Serialization fields

During serialization, spaCy will export several data fields used to restore different aspects of the object. If needed, you can exclude them from serialization by passing in the string names via the exclude argument.

Example

data = nlp.to_bytes(exclude=["tokenizer", "vocab"])
nlp.from_disk("./model-data", exclude=["ner"])

Name	Description
vocab	The shared Vocab.
tokenizer	Tokenization rules and exceptions.
meta	The meta data, available as Language.meta.
...	String names of pipeline components, e.g. "ner".

FactoryMeta

The FactoryMeta contains the information about the component and its default provided by the @Language.component or @Language.factory decorator. It's created whenever a component is defined and stored on the Language class for each component instance and factory instance.

Name	Type	Description
factory	str	The name of the registered component factory.
default_config	Dict[str, Any]	The default config, describing the default values of the factory arguments.
assigns	Iterable[str]	Doc or Token attributes assigned by this component, e.g. ["token.ent_id"]. Used for pipeline analysis.
requires	Iterable[str]	Doc or Token attributes required by this component, e.g. ["token.ent_id"]. Used for pipeline analysis.
retokenizes	bool	Whether the component changes tokenization. Used for pipeline analysis.
scores	Iterable[str]	All scores set by the components if it's trainable, e.g. ["ents_f", "ents_r", "ents_p"].
default_score_weights	Dict[str, float]	The scores to report during training, and their default weight towards the final score used to select the best model. Weights should sum to 1.0 per component and will be combined and normalized for the whole pipeline.