spaCy/website/docs/usage/v2.md
2020-07-01 21:26:39 +02:00

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What's New in v2.0 New features, backwards incompatibilities and migration guide
Summary
summary
New Features
features
Backwards Incompatibilities
incompat
Migrating from v1.x
migrating

We're very excited to finally introduce spaCy v2.0! On this page, you'll find a summary of the new features, information on the backwards incompatibilities, including a handy overview of what's been renamed or deprecated. To help you make the most of v2.0, we also re-wrote almost all of the usage guides and API docs, and added more real-world examples. If you're new to spaCy, or just want to brush up on some NLP basics and the details of the library, check out the spaCy 101 guide that explains the most important concepts with examples and illustrations.

Summary

This release features entirely new deep learning-powered models for spaCy's tagger, parser and entity recognizer. The new models are 10× smaller, 20% more accurate and even cheaper to run than the previous generation.

We've also made several usability improvements that are particularly helpful for production deployments. spaCy v2 now fully supports the Pickle protocol, making it easy to use spaCy with Apache Spark. The string-to-integer mapping is no longer stateful, making it easy to reconcile annotations made in different processes. Models are smaller and use less memory, and the APIs for serialization are now much more consistent. Custom pipeline components let you modify the Doc at any stage in the pipeline. You can now also add your own custom attributes, properties and methods to the Doc, Token and Span.

The main usability improvements you'll notice in spaCy v2.0 are around defining, training and loading your own models and components. The new neural network models make it much easier to train a model from scratch, or update an existing model with a few examples. In v1.x, the statistical models depended on the state of the Vocab. If you taught the model a new word, you would have to save and load a lot of data — otherwise the model wouldn't correctly recall the features of your new example. That's no longer the case.

Due to some clever use of hashing, the statistical models never change size, even as they learn new vocabulary items. The whole pipeline is also now fully differentiable. Even if you don't have explicitly annotated data, you can update spaCy using all the latest deep learning tricks like adversarial training, noise contrastive estimation or reinforcement learning.

New features

This section contains an overview of the most important new features and improvements. The API docs include additional deprecation notes. New methods and functions that were introduced in this version are marked with the tag 2.

Convolutional neural network models

Example

python -m spacy download en_core_web_sm
python -m spacy download de_core_news_sm
python -m spacy download xx_ent_wiki_sm

spaCy v2.0 features new neural models for tagging, parsing and entity recognition. The models have been designed and implemented from scratch specifically for spaCy, to give you an unmatched balance of speed, size and accuracy. The new models are 10× smaller, 20% more accurate, and even cheaper to run than the previous generation.

spaCy v2.0's new neural network models bring significant improvements in accuracy, especially for English Named Entity Recognition. The new en_core_web_lg model makes about 25% fewer mistakes than the corresponding v1.x model and is within 1% of the current state-of-the-art (Strubell et al., 2017). The v2.0 models are also cheaper to run at scale, as they require under 1 GB of memory per process.

Usage: Models directory

Improved processing pipelines

Example

# Set custom attributes
Doc.set_extension("my_attr", default=False)
Token.set_extension("my_attr", getter=my_token_getter)
assert doc._.my_attr, token._.my_attr

# Add components to the pipeline
my_component = lambda doc: doc
nlp.add_pipe(my_component)

It's now much easier to customize the pipeline with your own components: functions that receive a Doc object, modify and return it. Extensions let you write any attributes, properties and methods to the Doc, Token and Span. You can add data, implement new features, integrate other libraries with spaCy or plug in your own machine learning models.

The processing pipeline

API: Language, Doc.set_extension, Span.set_extension, Token.set_extension Usage: Processing pipelines Code: Pipeline examples

Text classification

Example

textcat = nlp.create_pipe("textcat")
nlp.add_pipe(textcat, last=True)
nlp.begin_training()
for itn in range(100):
   for doc, gold in train_data:
       nlp.update([doc], [gold])
doc = nlp("This is a text.")
print(doc.cats)

spaCy v2.0 lets you add text categorization models to spaCy pipelines. The model supports classification with multiple, non-mutually exclusive labels so multiple labels can apply at once. You can change the model architecture rather easily, but by default, the TextCategorizer class uses a convolutional neural network to assign position-sensitive vectors to each word in the document.

API: TextCategorizer, Doc.cats, GoldParse.cats Usage: Training a text classification model

Hash values instead of integer IDs

Example

doc = nlp("I love coffee")
assert doc.vocab.strings["coffee"] == 3197928453018144401
assert doc.vocab.strings[3197928453018144401] == "coffee"

beer_hash = doc.vocab.strings.add("beer")
assert doc.vocab.strings["beer"] == beer_hash
assert doc.vocab.strings[beer_hash] == "beer"

The StringStore now resolves all strings to hash values instead of integer IDs. This means that the string-to-int mapping no longer depends on the vocabulary state, making a lot of workflows much simpler, especially during training. Unlike integer IDs in spaCy v1.x, hash values will always match even across models. Strings can now be added explicitly using the new Stringstore.add method. A token's hash is available via token.orth.

API: StringStore Usage: Vocab, hashes and lexemes 101

Improved word vectors support

Example

for word, vector in vector_data:
    nlp.vocab.set_vector(word, vector)
nlp.vocab.vectors.from_glove("/path/to/vectors")
# Keep 10000 unique vectors and remap the rest
nlp.vocab.prune_vectors(10000)
nlp.to_disk("/model")

The new Vectors class helps the Vocab manage the vectors assigned to strings, and lets you assign vectors individually, or load in GloVe vectors from a directory. To help you strike a good balance between coverage and memory usage, the Vectors class lets you map multiple keys to the same row of the table. If you're using the spacy init-model command to create a vocabulary, pruning the vectors will be taken care of automatically if you set the --prune-vectors flag. Otherwise, you can use the new Vocab.prune_vectors.

API: Vectors, Vocab Usage: Word vectors and semantic similarity

Saving, loading and serialization

Example

nlp = spacy.load("en") # shortcut link
nlp = spacy.load("en_core_web_sm") # package
nlp = spacy.load("/path/to/en") # unicode path
nlp = spacy.load(Path("/path/to/en")) # pathlib Path

nlp.to_disk("/path/to/nlp")
nlp = English().from_disk("/path/to/nlp")

spaCy's serialization API has been made consistent across classes and objects. All container classes, i.e. Language, Doc, Vocab and StringStore now have a to_bytes(), from_bytes(), to_disk() and from_disk() method that supports the Pickle protocol.

The improved spacy.load makes loading models easier and more transparent. You can load a model by supplying its shortcut link, the name of an installed model package or a path. The Language class to initialize will be determined based on the model's settings. For a blank language, you can import the class directly, e.g. from spacy.lang.en import English or use spacy.blank().

API: spacy.load, Language.to_disk Usage: Models, Saving and loading

displaCy visualizer with Jupyter support

Example

from spacy import displacy
doc = nlp("This is a sentence about Facebook.")
displacy.serve(doc, style="dep") # run the web server
html = displacy.render(doc, style="ent") # generate HTML

Our popular dependency and named entity visualizers are now an official part of the spaCy library. displaCy can run a simple web server, or generate raw HTML markup or SVG files to be exported. You can pass in one or more docs, and customize the style. displaCy also auto-detects whether you're running Jupyter and will render the visualizations in your notebook.

API: displacy Usage: Visualizing spaCy

Improved language data and lazy loading

Language-specific data now lives in its own submodule, spacy.lang. Languages are lazy-loaded, i.e. only loaded when you import a Language class, or load a model that initializes one. This allows languages to contain more custom data, e.g. lemmatizer lookup tables, or complex regular expressions. The language data has also been tidied up and simplified. spaCy now also supports simple lookup-based lemmatization and many new languages!

API: Language Code: spacy/lang Usage: Adding languages

Revised matcher API and phrase matcher

Example

from spacy.matcher import Matcher, PhraseMatcher

matcher = Matcher(nlp.vocab)
matcher.add('HEARTS', None, [{"ORTH": "❤️", "OP": '+'}])

phrasematcher = PhraseMatcher(nlp.vocab)
phrasematcher.add("OBAMA", None, nlp("Barack Obama"))

Patterns can now be added to the matcher by calling matcher.add() with a match ID, an optional callback function to be invoked on each match, and one or more patterns. This allows you to write powerful, pattern-specific logic using only one matcher. For example, you might only want to merge some entity types, and set custom flags for other matched patterns. The new PhraseMatcher lets you efficiently match very large terminology lists using Doc objects as match patterns.

API: Matcher, PhraseMatcher Usage: Rule-based matching

Backwards incompatibilities

The following modules, classes and methods have changed between v1.x and v2.0.

Old New
spacy.download.en, spacy.download.de cli.download
spacy.en etc. spacy.lang.en etc.
spacy.en.word_sets spacy.lang.en.stop_words
spacy.orth spacy.lang.xx.lex_attrs
spacy.syntax.iterators spacy.lang.xx.syntax_iterators
spacy.tagger.Tagger spacy.pipeline.Tagger
spacy.cli.model spacy.cli.vocab
Language.save_to_directory Language.to_disk
Language.end_training Language.begin_training
Language.create_make_doc Language.tokenizer
Vocab.resize_vectors Vectors.resize
Vocab.load Vocab.load_lexemes Vocab.from_disk Vocab.from_bytes
Vocab.dump Vocab.to_disk Vocab.to_bytes
Vocab.load_vectors Vocab.load_vectors_from_bin_loc Vectors.from_disk Vectors.from_bytes Vectors.from_glove
Vocab.dump_vectors Vectors.to_disk Vectors.to_bytes
StringStore.load StringStore.from_disk StringStore.from_bytes
StringStore.dump StringStore.to_disk StringStore.to_bytes
Tokenizer.load Tokenizer.from_disk Tokenizer.from_bytes
Tagger.load Tagger.from_disk Tagger.from_bytes
Tagger.tag_names Tagger.labels
DependencyParser.load DependencyParser.from_disk DependencyParser.from_bytes
EntityRecognizer.load EntityRecognizer.from_disk EntityRecognizer.from_bytes
Matcher.load -
Matcher.add_pattern Matcher.add_entity Matcher.add PhraseMatcher.add
Matcher.get_entity Matcher.get
Matcher.has_entity Matcher.has_key
Doc.read_bytes Doc.to_bytes Doc.from_bytes Doc.to_disk Doc.from_disk
Token.is_ancestor_of Token.is_ancestor

Deprecated

The following methods are deprecated. They can still be used, but should be replaced.

Old New
Tokenizer.tokens_from_list Doc
Span.sent_start Span.is_sent_start

Migrating from spaCy 1.x

Because we'e made so many architectural changes to the library, we've tried to keep breaking changes to a minimum. A lot of projects follow the philosophy that if you're going to break anything, you may as well break everything. We think migration is easier if there's a logic to what has changed. We've therefore followed a policy of avoiding breaking changes to the Doc, Span and Token objects. This way, you can focus on only migrating the code that does training, loading and serialization — in other words, code that works with the nlp object directly. Code that uses the annotations should continue to work.

If you've trained your own models, keep in mind that your train and runtime inputs must match. This means you'll have to retrain your models with spaCy v2.0.

Document processing

The Language.pipe method allows spaCy to batch documents, which brings a significant performance advantage in v2.0. The new neural networks introduce some overhead per batch, so if you're processing a number of documents in a row, you should use nlp.pipe and process the texts as a stream.

- docs = (nlp(text) for text in texts)

+ docs = nlp.pipe(texts)

To make usage easier, there's now a boolean as_tuples keyword argument, that lets you pass in an iterator of (text, context) pairs, so you can get back an iterator of (doc, context) tuples.

Saving, loading and serialization

Double-check all calls to spacy.load() and make sure they don't use the path keyword argument. If you're only loading in binary data and not a model package that can construct its own Language class and pipeline, you should now use the Language.from_disk method.

- nlp = spacy.load("en", path="/model")

+ nlp = spacy.load("/model")
+ nlp = spacy.blank("en").from_disk("/model/data")

Review all other code that writes state to disk or bytes. All containers, now share the same, consistent API for saving and loading. Replace saving with to_disk() or to_bytes(), and loading with from_disk() and from_bytes().

- nlp.save_to_directory("/model")
- nlp.vocab.dump("/vocab")

+ nlp.to_disk("/model")
+ nlp.vocab.to_disk("/vocab")

If you've trained models with input from v1.x, you'll need to retrain them with spaCy v2.0. All previous models will not be compatible with the new version.

Processing pipelines and language data

If you're importing language data or Language classes, make sure to change your import statements to import from spacy.lang. If you've added your own custom language, it needs to be moved to spacy/lang/xx and adjusted accordingly.

- from spacy.en import English

+ from spacy.lang.en import English

If you've been using custom pipeline components, check out the new guide on processing pipelines. Pipeline components are now (name, func) tuples. Appending them to the pipeline still works but the add_pipe method now makes this much more convenient. Methods for removing, renaming, replacing and retrieving components have been added as well. Components can now be disabled by passing a list of their names to the disable keyword argument on load, or by using disable_pipes as a method or context manager:

- nlp = spacy.load("en_core_web_sm", tagger=False, entity=False)
- doc = nlp("I don't want parsed", parse=False)

+ nlp = spacy.load("en_core_web_sm", disable=["tagger", "ner"])
+ with nlp.disable_pipes("parser"):
+    doc = nlp("I don't want parsed")

To add spaCy's built-in pipeline components to your pipeline, you can still import and instantiate them directly but it's more convenient to use the new create_pipe method with the component name, i.e. 'tagger', 'parser', 'ner' or 'textcat'.

- from spacy.pipeline import Tagger
- tagger = Tagger(nlp.vocab)
- nlp.pipeline.insert(0, tagger)

+ tagger = nlp.create_pipe("tagger")
+ nlp.add_pipe(tagger, first=True)

Training

All built-in pipeline components are now subclasses of Pipe, fully trainable and serializable, and follow the same API. Instead of updating the model and telling spaCy when to stop, you can now explicitly call begin_training, which returns an optimizer you can pass into the update function. While update still accepts sequences of Doc and GoldParse objects, you can now also pass in a list of strings and dictionaries describing the annotations. We call this the "simple training style". This is also the recommended usage, as it removes one layer of abstraction from the training.

- for itn in range(1000):
-     for text, entities in train_data:
-         doc = Doc(text)
-         gold = GoldParse(doc, entities=entities)
-         nlp.update(doc, gold)
- nlp.end_training()
- nlp.save_to_directory("/model")

+ nlp.begin_training()
+ for itn in range(1000):
+     for texts, annotations in train_data:
+         nlp.update(texts, annotations)
+ nlp.to_disk("/model")

Attaching custom data to the Doc

Previously, you had to create a new container in order to attach custom data to a Doc object. This often required converting the Doc objects to and from arrays. In spaCy v2.0, you can set your own attributes, properties and methods on the Doc, Token and Span via custom extensions. This means that your application can and should only pass around Doc objects and refer to them as the single source of truth.

- doc = nlp("This is a regular doc")
- doc_array = doc.to_array(["ORTH", "POS"])
- doc_with_meta = {"doc_array": doc_array, "meta": get_doc_meta(doc_array)}

+ Doc.set_extension("meta", getter=get_doc_meta)
+ doc_with_meta = nlp(u'This is a doc with meta data')
+ meta = doc._.meta

If you wrap your extension attributes in a custom pipeline component, they will be assigned automatically when you call nlp on a text. If your application assigns custom data to spaCy's container objects, or includes other utilities that interact with the pipeline, consider moving this logic into its own extension module.

- doc = nlp("Doc with a standard pipeline")
- meta = get_meta(doc)

+ nlp.add_pipe(meta_component)
+ doc = nlp("Doc with a custom pipeline that assigns meta")
+ meta = doc._.meta

Strings and hash values

The change from integer IDs to hash values may not actually affect your code very much. However, if you're adding strings to the vocab manually, you now need to call StringStore.add explicitly. You can also now be sure that the string-to-hash mapping will always match across vocabularies.

- nlp.vocab.strings["coffee"]       # 3672
- other_nlp.vocab.strings["coffee"] # 40259

+ nlp.vocab.strings.add("coffee")
+ nlp.vocab.strings["coffee"]       # 3197928453018144401
+ other_nlp.vocab.strings["coffee"] # 3197928453018144401

Adding patterns and callbacks to the matcher

If you're using the matcher, you can now add patterns in one step. This should be easy to update simply merge the ID, callback and patterns into one call to Matcher.add(). The matcher now also supports string keys, which saves you an extra import. If you've been using acceptor functions, you'll need to move this logic into the on_match callbacks. The callback function is invoked on every match and will give you access to the doc, the index of the current match and all total matches. This lets you both accept or reject the match, and define the actions to be triggered.

- matcher.add_entity("GoogleNow", on_match=merge_phrases)
- matcher.add_pattern("GoogleNow", [{ORTH: "Google"}, {ORTH: "Now"}])

+ matcher.add("GoogleNow", merge_phrases, [{"ORTH": "Google"}, {"ORTH": "Now"}])

If you need to match large terminology lists, you can now also use the PhraseMatcher, which accepts Doc objects as match patterns and is more efficient than the regular, rule-based matcher.

- matcher = Matcher(nlp.vocab)
- matcher.add_entity("PRODUCT")
- for text in large_terminology_list
-     matcher.add_pattern("PRODUCT", [{ORTH: text}])

+ from spacy.matcher import PhraseMatcher
+ matcher = PhraseMatcher(nlp.vocab)
+ patterns = [nlp.make_doc(text) for text in large_terminology_list]
+ matcher.add("PRODUCT", None, *patterns)