mirror of https://github.com/explosion/spaCy.git
208 lines
9.9 KiB
Markdown
208 lines
9.9 KiB
Markdown
---
|
||
title: Matcher
|
||
teaser: Match sequences of tokens, based on pattern rules
|
||
tag: class
|
||
source: spacy/matcher/matcher.pyx
|
||
---
|
||
|
||
<Infobox title="Changed in v2.0" variant="warning">
|
||
|
||
As of spaCy 2.0, `Matcher.add_pattern` and `Matcher.add_entity` are deprecated
|
||
and have been replaced with a simpler [`Matcher.add`](/api/matcher#add) that
|
||
lets you add a list of patterns and a callback for a given match ID.
|
||
`Matcher.get_entity` is now called [`matcher.get`](/api/matcher#get).
|
||
`Matcher.load` (not useful, as it didn't allow specifying callbacks), and
|
||
`Matcher.has_entity` (now redundant) have been removed. The concept of "acceptor
|
||
functions" has also been retired – this logic can now be handled in the callback
|
||
functions.
|
||
|
||
</Infobox>
|
||
|
||
## 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 | Type | Description |
|
||
| --------------------------------------- | --------- | ------------------------------------------------------------------------------------------- |
|
||
| `vocab` | `Vocab` | The vocabulary object, which must be shared with the documents the matcher will operate on. |
|
||
| `validate` <Tag variant="new">2.1</Tag> | bool | Validate all patterns added to this matcher. |
|
||
| **RETURNS** | `Matcher` | The newly constructed object. |
|
||
|
||
## Matcher.\_\_call\_\_ {#call tag="method"}
|
||
|
||
Find all token sequences matching the supplied patterns on the `Doc`.
|
||
|
||
> #### Example
|
||
>
|
||
> ```python
|
||
> from spacy.matcher import Matcher
|
||
>
|
||
> matcher = Matcher(nlp.vocab)
|
||
> pattern = [{"LOWER": "hello"}, {"LOWER": "world"}]
|
||
> matcher.add("HelloWorld", None, pattern)
|
||
> doc = nlp(u'hello world!')
|
||
> matches = matcher(doc)
|
||
> ```
|
||
|
||
| Name | Type | Description |
|
||
| ----------- | ----- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
|
||
| `doc` | `Doc` | The document to match over. |
|
||
| **RETURNS** | list | 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. |
|
||
|
||
<Infobox title="Important note" variant="warning">
|
||
|
||
By default, the matcher **does not perform any action** on matches, like tagging
|
||
matched phrases with entity types. Instead, actions need to be specified when
|
||
**adding patterns or entities**, by passing in a callback function as the
|
||
`on_match` argument on [`add`](/api/matcher#add). This allows you to define
|
||
custom actions per pattern within the same matcher. For example, you might only
|
||
want to merge some entity types, and set custom flags for other matched
|
||
patterns. For more details and examples, see the usage guide on
|
||
[rule-based matching](/usage/rule-based-matching).
|
||
|
||
</Infobox>
|
||
|
||
## Matcher.pipe {#pipe tag="method"}
|
||
|
||
Match a stream of documents, yielding them in turn.
|
||
|
||
> #### Example
|
||
>
|
||
> ```python
|
||
> from spacy.matcher import Matcher
|
||
> matcher = Matcher(nlp.vocab)
|
||
> for doc in matcher.pipe(docs, batch_size=50):
|
||
> pass
|
||
> ```
|
||
|
||
| Name | Type | Description |
|
||
| --------------------------------------------- | -------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|
||
| `docs` | iterable | A stream of documents. |
|
||
| `batch_size` | int | The number of documents to accumulate into a working set. |
|
||
| `return_matches` <Tag variant="new">2.1</Tag> | bool | Yield the match lists along with the docs, making results `(doc, matches)` tuples. |
|
||
| `as_tuples` | bool | Interpret the input stream as `(doc, context)` tuples, and yield `(result, context)` tuples out. If both `return_matches` and `as_tuples` are `True`, the output will be a sequence of `((doc, matches), context)` tuples. |
|
||
| **YIELDS** | `Doc` | Documents, in order. |
|
||
|
||
## 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", None, [{"ORTH": "test"}])
|
||
> assert len(matcher) == 1
|
||
> ```
|
||
|
||
| Name | Type | Description |
|
||
| ----------- | ---- | -------------------- |
|
||
| **RETURNS** | int | The number of rules. |
|
||
|
||
## 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', None, [{'ORTH': 'test'}])
|
||
> assert 'Rule' in matcher
|
||
> ```
|
||
|
||
| Name | Type | Description |
|
||
| ----------- | ------- | ----------------------------------------------------- |
|
||
| `key` | unicode | The match ID. |
|
||
| **RETURNS** | bool | Whether the matcher contains rules for this match ID. |
|
||
|
||
## Matcher.add {#add tag="method" new="2"}
|
||
|
||
Add a rule to the matcher, consisting of an ID key, one or more patterns, and a
|
||
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)
|
||
> matcher.add("HelloWorld", on_match, [{"LOWER": "hello"}, {"LOWER": "world"}])
|
||
> matcher.add("GoogleMaps", on_match, [{"ORTH": "Google"}, {"ORTH": "Maps"}])
|
||
> doc = nlp(u"HELLO WORLD on Google Maps.")
|
||
> matches = matcher(doc)
|
||
> ```
|
||
|
||
| Name | Type | Description |
|
||
| ----------- | ------------------ | --------------------------------------------------------------------------------------------- |
|
||
| `match_id` | unicode | An ID for the thing you're matching. |
|
||
| `on_match` | callable or `None` | Callback function to act on matches. Takes the arguments `matcher`, `doc`, `i` and `matches`. |
|
||
| `*patterns` | list | Match pattern. A pattern consists of a list of dicts, where each dict describes a token. |
|
||
|
||
<Infobox title="Changed in v2.0" variant="warning">
|
||
|
||
As of spaCy 2.0, `Matcher.add_pattern` and `Matcher.add_entity` are deprecated
|
||
and have been replaced with a simpler [`Matcher.add`](/api/matcher#add) that
|
||
lets you add a list of patterns and a callback for a given match ID.
|
||
|
||
```diff
|
||
- 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"}])
|
||
```
|
||
|
||
</Infobox>
|
||
|
||
## 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", None, [{"ORTH": "test"}])
|
||
> assert "Rule" in matcher
|
||
> matcher.remove("Rule")
|
||
> assert "Rule" not in matcher
|
||
> ```
|
||
|
||
| Name | Type | Description |
|
||
| ----- | ------- | ------------------------- |
|
||
| `key` | unicode | The ID of the match rule. |
|
||
|
||
## 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", None, [{"ORTH": "test"}])
|
||
> on_match, patterns = matcher.get("Rule")
|
||
> ```
|
||
|
||
| Name | Type | Description |
|
||
| ----------- | ------- | --------------------------------------------- |
|
||
| `key` | unicode | The ID of the match rule. |
|
||
| **RETURNS** | tuple | The rule, as an `(on_match, patterns)` tuple. |
|