spaCy/website/docs/usage/101/_language-data.md
2019-10-01 13:22:13 +02:00

60 lines
5.0 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.

Every language is different and usually full of **exceptions and special
cases**, especially amongst the most common words. Some of these exceptions are
shared across languages, while others are **entirely specific** usually so
specific that they need to be hard-coded. The
[`lang`](https://github.com/explosion/spaCy/tree/master/spacy/lang) module
contains all language-specific data, organized in simple Python files. This
makes the data easy to update and extend.
The **shared language data** in the directory root includes rules that can be
generalized across languages for example, rules for basic punctuation, emoji,
emoticons, single-letter abbreviations and norms for equivalent tokens with
different spellings, like `"` and `”`. This helps the models make more accurate
predictions. The **individual language data** in a submodule contains rules that
are only relevant to a particular language. It also takes care of putting
together all components and creating the `Language` subclass for example,
`English` or `German`.
> ```python
> from spacy.lang.en import English
> from spacy.lang.de import German
>
> nlp_en = English() # Includes English data
> nlp_de = German() # Includes German data
> ```
![Language data architecture](../../images/language_data.svg)
| Name | Description |
| ---------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Stop words**<br />[`stop_words.py`][stop_words.py] | List of most common words of a language that are often useful to filter out, for example "and" or "I". Matching tokens will return `True` for `is_stop`. |
| **Tokenizer exceptions**<br />[`tokenizer_exceptions.py`][tokenizer_exceptions.py] | Special-case rules for the tokenizer, for example, contractions like "can't" and abbreviations with punctuation, like "U.K.". |
| **Norm exceptions**<br />[`norm_exceptions.py`][norm_exceptions.py] | Special-case rules for normalizing tokens to improve the model's predictions, for example on American vs. British spelling. |
| **Punctuation rules**<br />[`punctuation.py`][punctuation.py] | Regular expressions for splitting tokens, e.g. on punctuation or special characters like emoji. Includes rules for prefixes, suffixes and infixes. |
| **Character classes**<br />[`char_classes.py`][char_classes.py] | Character classes to be used in regular expressions, for example, latin characters, quotes, hyphens or icons. |
| **Lexical attributes**<br />[`lex_attrs.py`][lex_attrs.py] | Custom functions for setting lexical attributes on tokens, e.g. `like_num`, which includes language-specific words like "ten" or "hundred". |
| **Syntax iterators**<br />[`syntax_iterators.py`][syntax_iterators.py] | Functions that compute views of a `Doc` object based on its syntax. At the moment, only used for [noun chunks](/usage/linguistic-features#noun-chunks). |
| **Tag map**<br />[`tag_map.py`][tag_map.py] | Dictionary mapping strings in your tag set to [Universal Dependencies](http://universaldependencies.org/u/pos/all.html) tags. |
| **Morph rules**<br />[`morph_rules.py`][morph_rules.py] | Exception rules for morphological analysis of irregular words like personal pronouns. |
| **Lemmatizer**<br />[`spacy-lookups-data`][spacy-lookups-data] | Lemmatization rules or a lookup-based lemmatization table to assign base forms, for example "be" for "was". |
[stop_words.py]:
https://github.com/explosion/spaCy/tree/master/spacy/lang/en/stop_words.py
[tokenizer_exceptions.py]:
https://github.com/explosion/spaCy/tree/master/spacy/lang/de/tokenizer_exceptions.py
[norm_exceptions.py]:
https://github.com/explosion/spaCy/tree/master/spacy/lang/norm_exceptions.py
[punctuation.py]:
https://github.com/explosion/spaCy/tree/master/spacy/lang/punctuation.py
[char_classes.py]:
https://github.com/explosion/spaCy/tree/master/spacy/lang/char_classes.py
[lex_attrs.py]:
https://github.com/explosion/spaCy/tree/master/spacy/lang/en/lex_attrs.py
[syntax_iterators.py]:
https://github.com/explosion/spaCy/tree/master/spacy/lang/en/syntax_iterators.py
[tag_map.py]:
https://github.com/explosion/spaCy/tree/master/spacy/lang/en/tag_map.py
[morph_rules.py]:
https://github.com/explosion/spaCy/tree/master/spacy/lang/en/morph_rules.py
[spacy-lookups-data]: https://github.com/explosion/spacy-lookups-data