spaCy/website/docs/api/goldparse.md

206 lines
15 KiB
Markdown
Raw Blame History

This file contains ambiguous Unicode characters

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.

---
title: GoldParse
teaser: A collection for training annotations
tag: class
source: spacy/gold.pyx
---
## GoldParse.\_\_init\_\_ {#init tag="method"}
Create a `GoldParse`. Unlike annotations in `entities`, label annotations in
`cats` can overlap, i.e. a single word can be covered by multiple labelled
spans. The [`TextCategorizer`](/api/textcategorizer) component expects true
examples of a label to have the value `1.0`, and negative examples of a label to
have the value `0.0`. Labels not in the dictionary are treated as missing the
gradient for those labels will be zero.
| Name | Type | Description |
| ----------- | ----------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `doc` | `Doc` | The document the annotations refer to. |
| `words` | iterable | A sequence of unicode word strings. |
| `tags` | iterable | A sequence of strings, representing tag annotations. |
| `heads` | iterable | A sequence of integers, representing syntactic head offsets. |
| `deps` | iterable | A sequence of strings, representing the syntactic relation types. |
| `entities` | iterable | A sequence of named entity annotations, either as BILUO tag strings, or as `(start_char, end_char, label)` tuples, representing the entity positions. If BILUO tag strings, you can specify missing values by setting the tag to None. |
| `cats` | dict | Labels for text classification. Each key in the dictionary may be a string or an int, or a `(start_char, end_char, label)` tuple, indicating that the label is applied to only part of the document (usually a sentence). |
| **RETURNS** | `GoldParse` | The newly constructed object. |
## GoldParse.\_\_len\_\_ {#len tag="method"}
Get the number of gold-standard tokens.
| Name | Type | Description |
| ----------- | ---- | ----------------------------------- |
| **RETURNS** | int | The number of gold-standard tokens. |
## GoldParse.is_projective {#is_projective tag="property"}
Whether the provided syntactic annotations form a projective dependency tree.
| Name | Type | Description |
| ----------- | ---- | ----------------------------------------- |
| **RETURNS** | bool | Whether annotations form projective tree. |
## Attributes {#attributes}
| Name | Type | Description |
| --------------------------------- | ---- | -------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `words` | list | The words. |
| `tags` | list | The part-of-speech tag annotations. |
| `heads` | list | The syntactic head annotations. |
| `labels` | list | The syntactic relation-type annotations. |
| `ner` | list | The named entity annotations as BILUO tags. |
| `cand_to_gold` | list | The alignment from candidate tokenization to gold tokenization. |
| `gold_to_cand` | list | The alignment from gold tokenization to candidate tokenization. |
| `cats` <Tag variant="new">2</Tag> | list | Entries in the list should be either a label, or a `(start, end, label)` triple. The tuple form is used for categories applied to spans of the document. |
## Utilities {#util}
### gold.docs_to_json {#docs_to_json tag="function"}
Convert a list of Doc objects into the
[JSON-serializable format](/api/annotation#json-input) used by the
[`spacy train`](/api/cli#train) command.
> #### Example
>
> ```python
> from spacy.gold import docs_to_json
>
> doc = nlp(u"I like London")
> json_data = docs_to_json([doc])
> ```
| Name | Type | Description |
| ----------- | ---------------- | ------------------------------------------ |
| `docs` | iterable / `Doc` | The `Doc` object(s) to convert. |
| `id` | int | ID to assign to the JSON. Defaults to `0`. |
| **RETURNS** | list | The data in spaCy's JSON format. |
### gold.align {#align tag="function"}
Calculate alignment tables between two tokenizations, using the Levenshtein
algorithm. The alignment is case-insensitive.
<Infobox title="Important note" variant="warning">
The current implementation of the alignment algorithm assumes that both
tokenizations add up to the same string. For example, you'll be able to align
`["I", "'", "m"]` and `["I", "'m"]`, which both add up to `"I'm"`, but not
`["I", "'m"]` and `["I", "am"]`.
</Infobox>
> #### Example
>
> ```python
> from spacy.gold import align
>
> bert_tokens = ["obama", "'", "s", "podcast"]
> spacy_tokens = ["obama", "'s", "podcast"]
> alignment = align(bert_tokens, spacy_tokens)
> cost, a2b, b2a, a2b_multi, b2a_multi = alignment
> ```
| Name | Type | Description |
| ----------- | ----- | -------------------------------------------------------------------------- |
| `tokens_a` | list | String values of candidate tokens to align. |
| `tokens_b` | list | String values of reference tokens to align. |
| **RETURNS** | tuple | A `(cost, a2b, b2a, a2b_multi, b2a_multi)` tuple describing the alignment. |
The returned tuple contains the following alignment information:
> #### Example
>
> ```python
> a2b = array([0, -1, -1, 2])
> b2a = array([0, 2, 3])
> a2b_multi = {1: 1, 2: 1}
> b2a_multi = {}
> ```
>
> If `a2b[3] == 2`, that means that `tokens_a[3]` aligns to `tokens_b[2]`. If
> there's no one-to-one alignment for a token, it has the value `-1`.
| Name | Type | Description |
| ----------- | -------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------- |
| `cost` | int | The number of misaligned tokens. |
| `a2b` | `numpy.ndarray[ndim=1, dtype='int32']` | One-to-one mappings of indices in `tokens_a` to indices in `tokens_b`. |
| `b2a` | `numpy.ndarray[ndim=1, dtype='int32']` | One-to-one mappings of indices in `tokens_b` to indices in `tokens_a`. |
| `a2b_multi` | dict | A dictionary mapping indices in `tokens_a` to indices in `tokens_b`, where multiple tokens of `tokens_a` align to the same token of `tokens_b`. |
| `b2a_multi` | dict | A dictionary mapping indices in `tokens_b` to indices in `tokens_a`, where multiple tokens of `tokens_b` align to the same token of `tokens_a`. |
### gold.biluo_tags_from_offsets {#biluo_tags_from_offsets tag="function"}
Encode labelled spans into per-token tags, using the
[BILUO scheme](/api/annotation#biluo) (Begin, In, Last, Unit, Out). Returns a
list of unicode strings, describing the tags. Each tag string will be of the
form of either `""`, `"O"` or `"{action}-{label}"`, where action is one of
`"B"`, `"I"`, `"L"`, `"U"`. The string `"-"` is used where the entity offsets
don't align with the tokenization in the `Doc` object. The training algorithm
will view these as missing values. `O` denotes a non-entity token. `B` denotes
the beginning of a multi-token entity, `I` the inside of an entity of three or
more tokens, and `L` the end of an entity of two or more tokens. `U` denotes a
single-token entity.
> #### Example
>
> ```python
> from spacy.gold import biluo_tags_from_offsets
>
> doc = nlp(u"I like London.")
> entities = [(7, 13, "LOC")]
> tags = biluo_tags_from_offsets(doc, entities)
> assert tags == ["O", "O", "U-LOC", "O"]
> ```
| Name | Type | Description |
| ----------- | -------- | ----------------------------------------------------------------------------------------------------------------------------------------------- |
| `doc` | `Doc` | The document that the entity offsets refer to. The output tags will refer to the token boundaries within the document. |
| `entities` | iterable | A sequence of `(start, end, label)` triples. `start` and `end` should be character-offset integers denoting the slice into the original string. |
| **RETURNS** | list | Unicode strings, describing the [BILUO](/api/annotation#biluo) tags. |
### gold.offsets_from_biluo_tags {#offsets_from_biluo_tags tag="function"}
Encode per-token tags following the [BILUO scheme](/api/annotation#biluo) into
entity offsets.
> #### Example
>
> ```python
> from spacy.gold import offsets_from_biluo_tags
>
> doc = nlp(u"I like London.")
> tags = ["O", "O", "U-LOC", "O"]
> entities = offsets_from_biluo_tags(doc, tags)
> assert entities == [(7, 13, "LOC")]
> ```
| Name | Type | Description |
| ----------- | -------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `doc` | `Doc` | The document that the BILUO tags refer to. |
| `entities` | iterable | A sequence of [BILUO](/api/annotation#biluo) tags with each tag describing one token. Each tag string will be of the form of either `""`, `"O"` or `"{action}-{label}"`, where action is one of `"B"`, `"I"`, `"L"`, `"U"`. |
| **RETURNS** | list | A sequence of `(start, end, label)` triples. `start` and `end` will be character-offset integers denoting the slice into the original string. |
### gold.spans_from_biluo_tags {#spans_from_biluo_tags tag="function" new="2.1"}
Encode per-token tags following the [BILUO scheme](/api/annotation#biluo) into
[`Span`](/api/span) objects. This can be used to create entity spans from
token-based tags, e.g. to overwrite the `doc.ents`.
> #### Example
>
> ```python
> from spacy.gold import offsets_from_biluo_tags
>
> doc = nlp(u"I like London.")
> tags = ["O", "O", "U-LOC", "O"]
> doc.ents = spans_from_biluo_tags(doc, tags)
> ```
| Name | Type | Description |
| ----------- | -------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `doc` | `Doc` | The document that the BILUO tags refer to. |
| `entities` | iterable | A sequence of [BILUO](/api/annotation#biluo) tags with each tag describing one token. Each tag string will be of the form of either `""`, `"O"` or `"{action}-{label}"`, where action is one of `"B"`, `"I"`, `"L"`, `"U"`. |
| **RETURNS** | list | A sequence of `Span` objects with added entity labels. |