mirror of
https://github.com/explosion/spaCy.git
synced 2024-11-11 04:08:09 +03:00
247 lines
14 KiB
Markdown
247 lines
14 KiB
Markdown
---
|
||
title: Matcher
|
||
teaser: Match sequences of tokens, based on pattern rules
|
||
tag: class
|
||
source: spacy/matcher/matcher.pyx
|
||
---
|
||
|
||
The `Matcher` lets you find words and phrases using rules describing their token
|
||
attributes. Rules can refer to token annotations (like the text or
|
||
part-of-speech tags), as well as lexical attributes like `Token.is_punct`.
|
||
Applying the matcher to a [`Doc`](/api/doc) gives you access to the matched
|
||
tokens in context. For in-depth examples and workflows for combining rules and
|
||
statistical models, see the [usage guide](/usage/rule-based-matching) on
|
||
rule-based matching.
|
||
|
||
## Pattern format {#patterns}
|
||
|
||
> ```json
|
||
> ### Example
|
||
> [
|
||
> {"LOWER": "i"},
|
||
> {"LEMMA": {"IN": ["like", "love"]}},
|
||
> {"POS": "NOUN", "OP": "+"}
|
||
> ]
|
||
> ```
|
||
|
||
A pattern added to the `Matcher` consists of a list of dictionaries. Each
|
||
dictionary describes **one token** and its attributes. The available token
|
||
pattern keys correspond to a number of
|
||
[`Token` attributes](/api/token#attributes). The supported attributes for
|
||
rule-based matching are:
|
||
|
||
| Attribute | Description |
|
||
| ----------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------- |
|
||
| `ORTH` | The exact verbatim text of a token. ~~str~~ |
|
||
| `TEXT` <Tag variant="new">2.1</Tag> | The exact verbatim text of a token. ~~str~~ |
|
||
| `LOWER` | The lowercase form of the token text. ~~str~~ |
|
||
| `LENGTH` | The length of the token text. ~~int~~ |
|
||
| `IS_ALPHA`, `IS_ASCII`, `IS_DIGIT` | Token text consists of alphabetic characters, ASCII characters, digits. ~~bool~~ |
|
||
| `IS_LOWER`, `IS_UPPER`, `IS_TITLE` | Token text is in lowercase, uppercase, titlecase. ~~bool~~ |
|
||
| `IS_PUNCT`, `IS_SPACE`, `IS_STOP` | Token is punctuation, whitespace, stop word. ~~bool~~ |
|
||
| `IS_SENT_START` | Token is start of sentence. ~~bool~~ |
|
||
| `LIKE_NUM`, `LIKE_URL`, `LIKE_EMAIL` | Token text resembles a number, URL, email. ~~bool~~ |
|
||
| `SPACY` | Token has a trailing space. ~~bool~~ |
|
||
| `POS`, `TAG`, `MORPH`, `DEP`, `LEMMA`, `SHAPE` | The token's simple and extended part-of-speech tag, morphological analysis, dependency label, lemma, shape. ~~str~~ |
|
||
| `ENT_TYPE` | The token's entity label. ~~str~~ |
|
||
| `_` <Tag variant="new">2.1</Tag> | Properties in [custom extension attributes](/usage/processing-pipelines#custom-components-attributes). ~~Dict[str, Any]~~ |
|
||
| `OP` | Operator or quantifier to determine how often to match a token pattern. ~~str~~ |
|
||
|
||
Operators and quantifiers define **how often** a token pattern should be
|
||
matched:
|
||
|
||
> ```json
|
||
> ### Example
|
||
> [
|
||
> {"POS": "ADJ", "OP": "*"},
|
||
> {"POS": "NOUN", "OP": "+"}
|
||
> ]
|
||
> ```
|
||
|
||
| OP | Description |
|
||
| --- | ---------------------------------------------------------------- |
|
||
| `!` | Negate the pattern, by requiring it to match exactly 0 times. |
|
||
| `?` | Make the pattern optional, by allowing it to match 0 or 1 times. |
|
||
| `+` | Require the pattern to match 1 or more times. |
|
||
| `*` | Allow the pattern to match 0 or more times. |
|
||
|
||
Token patterns can also map to a **dictionary of properties** instead of a
|
||
single value to indicate whether the expected value is a member of a list or how
|
||
it compares to another value.
|
||
|
||
> ```json
|
||
> ### Example
|
||
> [
|
||
> {"LEMMA": {"IN": ["like", "love", "enjoy"]}},
|
||
> {"POS": "PROPN", "LENGTH": {">=": 10}},
|
||
> ]
|
||
> ```
|
||
|
||
| Attribute | Description |
|
||
| -------------------------- | ------------------------------------------------------------------------------------------------------- |
|
||
| `IN` | Attribute value is member of a list. ~~Any~~ |
|
||
| `NOT_IN` | Attribute value is _not_ member of a list. ~~Any~~ |
|
||
| `ISSUBSET` | Attribute values (for `MORPH`) are a subset of a list. ~~Any~~ |
|
||
| `ISSUPERSET` | Attribute values (for `MORPH`) are a superset of a list. ~~Any~~ |
|
||
| `==`, `>=`, `<=`, `>`, `<` | Attribute value is equal, greater or equal, smaller or equal, greater or smaller. ~~Union[int, float]~~ |
|
||
|
||
## Matcher.\_\_init\_\_ {#init tag="method"}
|
||
|
||
Create the rule-based `Matcher`. If `validate=True` is set, all patterns added
|
||
to the matcher will be validated against a JSON schema and a `MatchPatternError`
|
||
is raised if problems are found. Those can include incorrect types (e.g. a
|
||
string where an integer is expected) or unexpected property names.
|
||
|
||
> #### Example
|
||
>
|
||
> ```python
|
||
> from spacy.matcher import Matcher
|
||
> matcher = Matcher(nlp.vocab)
|
||
> ```
|
||
|
||
| Name | Description |
|
||
| --------------------------------------- | ----------------------------------------------------------------------------------------------------- |
|
||
| `vocab` | The vocabulary object, which must be shared with the documents the matcher will operate on. ~~Vocab~~ |
|
||
| `validate` <Tag variant="new">2.1</Tag> | Validate all patterns added to this matcher. ~~bool~~ |
|
||
|
||
## Matcher.\_\_call\_\_ {#call tag="method"}
|
||
|
||
Find all token sequences matching the supplied patterns on the `Doc` or `Span`.
|
||
|
||
> #### Example
|
||
>
|
||
> ```python
|
||
> from spacy.matcher import Matcher
|
||
>
|
||
> matcher = Matcher(nlp.vocab)
|
||
> pattern = [{"LOWER": "hello"}, {"LOWER": "world"}]
|
||
> matcher.add("HelloWorld", [pattern])
|
||
> doc = nlp("hello world!")
|
||
> matches = matcher(doc)
|
||
> ```
|
||
|
||
| Name | Description |
|
||
| ------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `doclike` | The `Doc` or `Span` to match over. ~~Union[Doc, Span]~~ |
|
||
| _keyword-only_ | |
|
||
| `as_spans` <Tag variant="new">3</Tag> | Instead of tuples, return a list of [`Span`](/api/span) objects of the matches, with the `match_id` assigned as the span label. Defaults to `False`. ~~bool~~ |
|
||
| **RETURNS** | A list of `(match_id, start, end)` tuples, describing the matches. A match tuple describes a span `doc[start:end`]. The `match_id` is the ID of the added match pattern. If `as_spans` is set to `True`, a list of `Span` objects is returned instead. ~~Union[List[Tuple[int, int, int]], List[Span]]~~ |
|
||
|
||
## Matcher.\_\_len\_\_ {#len tag="method" new="2"}
|
||
|
||
Get the number of rules added to the matcher. Note that this only returns the
|
||
number of rules (identical with the number of IDs), not the number of individual
|
||
patterns.
|
||
|
||
> #### Example
|
||
>
|
||
> ```python
|
||
> matcher = Matcher(nlp.vocab)
|
||
> assert len(matcher) == 0
|
||
> matcher.add("Rule", [[{"ORTH": "test"}]])
|
||
> assert len(matcher) == 1
|
||
> ```
|
||
|
||
| Name | Description |
|
||
| ----------- | ---------------------------- |
|
||
| **RETURNS** | The number of rules. ~~int~~ |
|
||
|
||
## Matcher.\_\_contains\_\_ {#contains tag="method" new="2"}
|
||
|
||
Check whether the matcher contains rules for a match ID.
|
||
|
||
> #### Example
|
||
>
|
||
> ```python
|
||
> matcher = Matcher(nlp.vocab)
|
||
> assert "Rule" not in matcher
|
||
> matcher.add("Rule", [[{'ORTH': 'test'}]])
|
||
> assert "Rule" in matcher
|
||
> ```
|
||
|
||
| Name | Description |
|
||
| ----------- | -------------------------------------------------------------- |
|
||
| `key` | The match ID. ~~str~~ |
|
||
| **RETURNS** | Whether the matcher contains rules for this match ID. ~~bool~~ |
|
||
|
||
## Matcher.add {#add tag="method" new="2"}
|
||
|
||
Add a rule to the matcher, consisting of an ID key, one or more patterns, and an
|
||
optional callback function to act on the matches. The callback function will
|
||
receive the arguments `matcher`, `doc`, `i` and `matches`. If a pattern already
|
||
exists for the given ID, the patterns will be extended. An `on_match` callback
|
||
will be overwritten.
|
||
|
||
> #### Example
|
||
>
|
||
> ```python
|
||
> def on_match(matcher, doc, id, matches):
|
||
> print('Matched!', matches)
|
||
>
|
||
> matcher = Matcher(nlp.vocab)
|
||
> patterns = [
|
||
> [{"LOWER": "hello"}, {"LOWER": "world"}],
|
||
> [{"ORTH": "Google"}, {"ORTH": "Maps"}]
|
||
> ]
|
||
> matcher.add("TEST_PATTERNS", patterns)
|
||
> doc = nlp("HELLO WORLD on Google Maps.")
|
||
> matches = matcher(doc)
|
||
> ```
|
||
|
||
<Infobox title="Changed in v3.0" variant="warning">
|
||
|
||
As of spaCy v3.0, `Matcher.add` takes a list of patterns as the second argument
|
||
(instead of a variable number of arguments). The `on_match` callback becomes an
|
||
optional keyword argument.
|
||
|
||
```diff
|
||
patterns = [[{"TEXT": "Google"}, {"TEXT": "Now"}], [{"TEXT": "GoogleNow"}]]
|
||
- matcher.add("GoogleNow", on_match, *patterns)
|
||
+ matcher.add("GoogleNow", patterns, on_match=on_match)
|
||
```
|
||
|
||
</Infobox>
|
||
|
||
| Name | Description |
|
||
| ----------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `match_id` | An ID for the thing you're matching. ~~str~~ |
|
||
| `patterns` | Match pattern. A pattern consists of a list of dicts, where each dict describes a token. ~~List[List[Dict[str, Any]]]~~ |
|
||
| _keyword-only_ | |
|
||
| `on_match` | Callback function to act on matches. Takes the arguments `matcher`, `doc`, `i` and `matches`. ~~Optional[Callable[[Matcher, Doc, int, List[tuple], Any]]~~ |
|
||
| `greedy` <Tag variant="new">3</Tag> | Optional filter for greedy matches. Can either be `"FIRST"` or `"LONGEST"`. ~~Optional[str]~~ |
|
||
|
||
## Matcher.remove {#remove tag="method" new="2"}
|
||
|
||
Remove a rule from the matcher. A `KeyError` is raised if the match ID does not
|
||
exist.
|
||
|
||
> #### Example
|
||
>
|
||
> ```python
|
||
> matcher.add("Rule", [[{"ORTH": "test"}]])
|
||
> assert "Rule" in matcher
|
||
> matcher.remove("Rule")
|
||
> assert "Rule" not in matcher
|
||
> ```
|
||
|
||
| Name | Description |
|
||
| ----- | --------------------------------- |
|
||
| `key` | The ID of the match rule. ~~str~~ |
|
||
|
||
## Matcher.get {#get tag="method" new="2"}
|
||
|
||
Retrieve the pattern stored for a key. Returns the rule as an
|
||
`(on_match, patterns)` tuple containing the callback and available patterns.
|
||
|
||
> #### Example
|
||
>
|
||
> ```python
|
||
> matcher.add("Rule", [[{"ORTH": "test"}]])
|
||
> on_match, patterns = matcher.get("Rule")
|
||
> ```
|
||
|
||
| Name | Description |
|
||
| ----------- | --------------------------------------------------------------------------------------------- |
|
||
| `key` | The ID of the match rule. ~~str~~ |
|
||
| **RETURNS** | The rule, as an `(on_match, patterns)` tuple. ~~Tuple[Optional[Callable], List[List[dict]]]~~ |
|