mirror of https://github.com/explosion/spaCy.git
127 lines
4.8 KiB
Plaintext
127 lines
4.8 KiB
Plaintext
//- 💫 DOCS > USAGE > PROCESSING PIPELINES > EXAMPLES
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p
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| To see real-world examples of pipeline factories and components in action,
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| you can have a look at the source of spaCy's built-in components, e.g.
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| the #[+api("tagger") #[code Tagger]], #[+api("parser") #[code Parser]] or
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| #[+api("entityrecognizer") #[code EntityRecongnizer]].
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+h(3, "example1") Example: Custom sentence segmentation logic
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p
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| Let's say you want to implement custom logic to improve spaCy's sentence
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| boundary detection. Currently, sentence segmentation is based on the
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| dependency parse, which doesn't always produce ideal results. The custom
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| logic should therefore be applied #[strong after] tokenization, but
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| #[strong before] the dependency parsing – this way, the parser can also
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| take advantage of the sentence boundaries.
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+code.
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def sbd_component(doc):
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for i, token in enumerate(doc[:-2]):
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# define sentence start if period + titlecase token
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if token.text == '.' and doc[i+1].is_title:
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doc[i+1].sent_start = True
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return doc
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p
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| In this case, we simply want to add the component to the existing
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| pipeline of the English model. We can do this by inserting it at index 0
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| of #[code nlp.pipeline]:
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+code.
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nlp = spacy.load('en')
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nlp.pipeline.insert(0, sbd_component)
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p
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| When you call #[code nlp] on some text, spaCy will tokenize it to create
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| a #[code Doc] object, and first call #[code sbd_component] on it, followed
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| by the model's default pipeline.
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+h(3, "example2") Example: Sentiment model
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p
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| Let's say you have trained your own document sentiment model on English
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| text. After tokenization, you want spaCy to first execute the
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| #[strong default tensorizer], followed by a custom
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| #[strong sentiment component] that adds a #[code .sentiment]
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| property to the #[code Doc], containing your model's sentiment precition.
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p
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| Your component class will have a #[code from_disk()] method that spaCy
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| calls to load the model data. When called, the component will compute
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| the sentiment score, add it to the #[code Doc] and return the modified
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| document. Optionally, the component can include an #[code update()] method
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| to allow training the model.
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+code.
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import pickle
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from pathlib import Path
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class SentimentComponent(object):
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def __init__(self, vocab):
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self.weights = None
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def __call__(self, doc):
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doc.sentiment = sum(self.weights*doc.vector) # set sentiment property
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return doc
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def from_disk(self, path): # path = model path + factory ID ('sentiment')
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self.weights = pickle.load(Path(path) / 'weights.bin') # load weights
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return self
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def update(self, doc, gold): # update weights – allows training!
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prediction = sum(self.weights*doc.vector)
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self.weights -= 0.001*doc.vector*(prediction-gold.sentiment)
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p
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| The factory will initialise the component with the #[code Vocab] object.
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| To be able to add it to your model's pipeline as #[code 'sentiment'],
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| it also needs to be registered via
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| #[+api("spacy#set_factory") #[code set_factory()]].
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+code.
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def sentiment_factory(vocab):
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component = SentimentComponent(vocab) # initialise component
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return component
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spacy.set_factory('sentiment', sentiment_factory)
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p
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| The above code should be #[strong shipped with your model]. You can use
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| the #[+api("cli#package") #[code package]] command to create all required
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| files and directories. The model package will include an
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| #[+src(gh("spacy-dev-resources", "templates/model/en_model_name/__init__.py")) #[code __init__.py]]
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| with a #[code load()] method, that will initialise the language class with
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| the model's pipeline and call the #[code from_disk()] method to load
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| the model data.
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p
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| In the model package's meta.json, specify the language class and pipeline
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| IDs:
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+code("meta.json (excerpt)", "json").
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{
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"name": "sentiment_model",
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"lang": "en",
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"version": "1.0.0",
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"spacy_version": ">=2.0.0,<3.0.0",
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"pipeline": ["tensorizer", "sentiment"]
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}
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p
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| When you load your new model, spaCy will call the model's #[code load()]
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| method. This will return a #[code Language] object with a pipeline
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| containing the default tensorizer, and the sentiment component returned
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| by your custom #[code "sentiment"] factory.
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+code.
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nlp = spacy.load('en_sentiment_model')
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doc = nlp(u'I love pizza')
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assert doc.sentiment
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+infobox("Saving and loading models")
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| For more information and a detailed guide on how to package your model,
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| see the documentation on
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| #[+a("/usage/training#saving-loading") saving and loading models].
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