spaCy/website/docs/api/goldparse.md
2019-02-27 12:07:35 +01:00

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GoldParse A collection for training annotations class spacy/gold.pyx

GoldParse.__init__

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 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__

Get the number of gold-standard tokens.

Name Type Description
RETURNS int The number of gold-standard tokens.

GoldParse.is_projective

Whether the provided syntactic annotations form a projective dependency tree.

Name Type Description
RETURNS bool Whether annotations form projective tree.

Attributes

Name Type Description
tags list The part-of-speech tag annotations.
heads list The syntactic head annotations.
labels list The syntactic relation-type annotations.
ents list The named entity annotations.
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 2 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

gold.biluo_tags_from_offsets

Encode labelled spans into per-token tags, using the BILUO scheme (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

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 tags.

gold.offsets_from_biluo_tags

Encode per-token tags following the BILUO scheme into entity offsets.

Example

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 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

Encode per-token tags following the BILUO scheme into Span objects. This can be used to create entity spans from token-based tags, e.g. to overwrite the doc.ents.

Example

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 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.