spaCy/website/docs/usage/101/_pos-deps.md

64 lines
3.2 KiB
Markdown
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

After tokenization, spaCy can **parse** and **tag** a given `Doc`. This is where
the trained pipeline and its statistical models come in, which enable spaCy to
**make predictions** of which tag or label most likely applies in this context.
A trained component includes binary data that is produced by showing a system
enough examples for it to make predictions that generalize across the language
for example, a word following "the" in English is most likely a noun.
Linguistic annotations are available as
[`Token` attributes](/api/token#attributes). Like many NLP libraries, spaCy
**encodes all strings to hash values** to reduce memory usage and improve
efficiency. So to get the readable string representation of an attribute, we
need to add an underscore `_` to its name:
```python
### {executable="true"}
import spacy
nlp = spacy.load("en_core_web_sm")
doc = nlp("Apple is looking at buying U.K. startup for $1 billion")
for token in doc:
print(token.text, token.lemma_, token.pos_, token.tag_, token.dep_,
token.shape_, token.is_alpha, token.is_stop)
```
> - **Text:** The original word text.
> - **Lemma:** The base form of the word.
> - **POS:** The simple [UPOS](https://universaldependencies.org/u/pos/)
> part-of-speech tag.
> - **Tag:** The detailed part-of-speech tag.
> - **Dep:** Syntactic dependency, i.e. the relation between tokens.
> - **Shape:** The word shape capitalization, punctuation, digits.
> - **is alpha:** Is the token an alpha character?
> - **is stop:** Is the token part of a stop list, i.e. the most common words of
> the language?
| Text | Lemma | POS | Tag | Dep | Shape | alpha | stop |
| ------- | ------- | ------- | ----- | ---------- | ------- | ------- | ------- |
| Apple | apple | `PROPN` | `NNP` | `nsubj` | `Xxxxx` | `True` | `False` |
| is | be | `AUX` | `VBZ` | `aux` | `xx` | `True` | `True` |
| looking | look | `VERB` | `VBG` | `ROOT` | `xxxx` | `True` | `False` |
| at | at | `ADP` | `IN` | `prep` | `xx` | `True` | `True` |
| buying | buy | `VERB` | `VBG` | `pcomp` | `xxxx` | `True` | `False` |
| U.K. | u.k. | `PROPN` | `NNP` | `compound` | `X.X.` | `False` | `False` |
| startup | startup | `NOUN` | `NN` | `dobj` | `xxxx` | `True` | `False` |
| for | for | `ADP` | `IN` | `prep` | `xxx` | `True` | `True` |
| \$ | \$ | `SYM` | `$` | `quantmod` | `$` | `False` | `False` |
| 1 | 1 | `NUM` | `CD` | `compound` | `d` | `False` | `False` |
| billion | billion | `NUM` | `CD` | `pobj` | `xxxx` | `True` | `False` |
> #### Tip: Understanding tags and labels
>
> Most of the tags and labels look pretty abstract, and they vary between
> languages. `spacy.explain` will show you a short description for example,
> `spacy.explain("VBZ")` returns "verb, 3rd person singular present".
Using spaCy's built-in [displaCy visualizer](/usage/visualizers), here's what
our example sentence and its dependencies look like:
import DisplaCyLongHtml from 'images/displacy-long.html'; import { Iframe } from
'components/embed'
<Iframe title="displaCy visualization of dependencies and entities" html={DisplaCyLongHtml} height={450} />