spaCy/website/docs/api/matcher.md

---
title: Matcher
teaser: Match sequences of tokens, based on pattern rules
tag: class
source: spacy/matcher/matcher.pyx
---

## 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` 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        | Type         | Description                                                                                                                                                              |
| ----------- | ------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `doclike`   | `Doc`/`Span` | The `Doc` or `Span` 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. |

## 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", [[{"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", [[{'ORTH': 'test'}]])
> assert "Rule" in matcher
> ```

| Name        | Type | Description                                           |
| ----------- | ---- | ----------------------------------------------------- |
| `key`       | str  | 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)
> 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           | Type               | Description                                                                                   |
| -------------- | ------------------ | --------------------------------------------------------------------------------------------- |
| `match_id`     | str                | An ID for the thing you're matching.                                                          |
| `patterns`     | list               | Match pattern. A pattern consists of a list of dicts, where each dict describes a token.      |
| _keyword-only_ |                    |                                                                                               |
| `on_match`     | callable or `None` | Callback function to act on matches. Takes the arguments `matcher`, `doc`, `i` and `matches`. |

## 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  | Type | Description               |
| ----- | ---- | ------------------------- |
| `key` | str  | 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", [[{"ORTH": "test"}]])
> on_match, patterns = matcher.get("Rule")
> ```

| Name        | Type  | Description                                   |
| ----------- | ----- | --------------------------------------------- |
| `key`       | str   | The ID of the match rule.                     |
| **RETURNS** | tuple | The rule, as an `(on_match, patterns)` tuple. |