mirror of
https://github.com/explosion/spaCy.git
synced 2024-12-27 18:36:36 +03:00
666 lines
28 KiB
Plaintext
666 lines
28 KiB
Plaintext
//- 💫 DOCS > USAGE > ADDING LANGUAGES
|
||
|
||
include ../../_includes/_mixins
|
||
|
||
p
|
||
| Adding full support for a language touches many different parts of the
|
||
| spaCy library. This guide explains how to fit everything together, and
|
||
| points you to the specific workflows for each component. Obviously,
|
||
| there are lots of ways you can organise your code when you implement
|
||
| your own #[+api("language") #[code Language]] class. This guide will
|
||
| focus on how it's done within spaCy. For full language support, we'll
|
||
| need to:
|
||
|
||
+list("numbers")
|
||
+item
|
||
| Create a #[strong #[code Language] subclass].
|
||
+item
|
||
| Define custom #[strong language data], like a stop list and tokenizer
|
||
| exceptions.
|
||
+item
|
||
| #[strong Test] the new language tokenizer.
|
||
+item
|
||
| #[strong Build the vocabulary], including word frequencies, Brown
|
||
| clusters and word vectors.
|
||
+item
|
||
| Set up a #[strong model direcory] and #[strong train] the tagger and
|
||
| parser.
|
||
|
||
p
|
||
| For some languages, you may also want to develop a solution for
|
||
| lemmatization and morphological analysis.
|
||
|
||
+h(2, "language-subclass") Creating a #[code Language] subclass
|
||
|
||
p
|
||
| Language-specific code and resources should be organised into a
|
||
| subpackage of spaCy, named according to the language's
|
||
| #[+a("https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes") ISO code].
|
||
| For instance, code and resources specific to Spanish are placed into a
|
||
| directory #[code spacy/lang/es], which can be imported as
|
||
| #[code spacy.lang.es].
|
||
|
||
p
|
||
| To get started, you can use our
|
||
| #[+src(gh("spacy-dev-resources", "templates/new_language")) templates]
|
||
| for the most important files. Here's what the class template looks like:
|
||
|
||
+code("__init__.py (excerpt)").
|
||
# import language-specific data
|
||
from .stop_words import STOP_WORDS
|
||
from .tokenizer_exceptions import TOKENIZER_EXCEPTIONS
|
||
from .lex_attrs import LEX_ATTRS
|
||
|
||
from ..tokenizer_exceptions import BASE_EXCEPTIONS
|
||
from ...language import Language
|
||
from ...attrs import LANG
|
||
from ...util import update_exc
|
||
|
||
# create Defaults class in the module scope (necessary for pickling!)
|
||
class XxxxxDefaults(Language.Defaults):
|
||
lex_attr_getters = dict(Language.Defaults.lex_attr_getters)
|
||
lex_attr_getters[LANG] = lambda text: 'xx' # language ISO code
|
||
|
||
# optional: replace flags with custom functions, e.g. like_num()
|
||
lex_attr_getters.update(LEX_ATTRS)
|
||
|
||
# merge base exceptions and custom tokenizer exceptions
|
||
tokenizer_exceptions = update_exc(BASE_EXCEPTIONS, TOKENIZER_EXCEPTIONS)
|
||
stop_words = set(STOP_WORDS)
|
||
|
||
# create actual Language class
|
||
class Xxxxx(Language):
|
||
lang = 'xx' # language ISO code
|
||
Defaults = XxxxxDefaults # override defaults
|
||
|
||
# set default export – this allows the language class to be lazy-loaded
|
||
__all__ = ['Xxxxx']
|
||
|
||
+aside("Why lazy-loading?")
|
||
| Some languages contain large volumes of custom data, like lemmatizer
|
||
| loopup tables, or complex regular expression that are expensive to
|
||
| compute. As of spaCy v2.0, #[code Language] classes are not imported on
|
||
| initialisation and are only loaded when you import them directly, or load
|
||
| a model that requires a language to be loaded. To lazy-load languages in
|
||
| your application, you can use the
|
||
| #[+api("util#get_lang_class") #[code util.get_lang_class()]] helper
|
||
| function with the two-letter language code as its argument.
|
||
|
||
+h(2, "language-data") Adding language data
|
||
|
||
p
|
||
| Every language is full of exceptions and special cases, especially
|
||
| amongst the most common words. Some of these exceptions are shared
|
||
| between multiple languages, while others are entirely idiosyncratic.
|
||
| spaCy makes it easy to deal with these exceptions on a case-by-case
|
||
| basis, by defining simple rules and exceptions. The exceptions data is
|
||
| defined in Python the
|
||
| #[+src(gh("spacy-dev-resources", "templates/new_language")) language data],
|
||
| so that Python functions can be used to help you generalise and combine
|
||
| the data as you require.
|
||
|
||
p
|
||
| Here's an overview of the individual components that can be included
|
||
| in the language data. For more details on them, see the sections below.
|
||
|
||
+image
|
||
include ../../assets/img/docs/language_data.svg
|
||
.u-text-right
|
||
+button("/assets/img/docs/language_data.svg", false, "secondary").u-text-tag View large graphic
|
||
|
||
+table(["File name", "Variables", "Description"])
|
||
+row
|
||
+cell #[+src(gh("spacy-dev-resources", "templates/new_language/stop_words.py")) stop_words.py]
|
||
+cell #[code STOP_WORDS] (set)
|
||
+cell
|
||
| List of most common words. Matching tokens will return #[code True]
|
||
| for #[code is_stop].
|
||
|
||
+row
|
||
+cell #[+src(gh("spacy-dev-resources", "templates/new_language/tokenizer_exceptions.py")) tokenizer_exceptions.py]
|
||
+cell #[code TOKENIZER_EXCEPTIONS] (dict), #[code TOKEN_MATCH] (regex)
|
||
+cell
|
||
| Special-case rules for the tokenizer, for example, contractions
|
||
| and abbreviations containing punctuation.
|
||
|
||
+row
|
||
+cell #[+src(gh("spaCy", "spacy/lang/punctuation.py")) punctuation.py]
|
||
+cell
|
||
| #[code TOKENIZER_PREFIXES], #[code TOKENIZER_SUFFIXES],
|
||
| #[code TOKENIZER_INFIXES] (dicts)
|
||
+cell Regular expressions for splitting tokens, e.g. on punctuation.
|
||
|
||
+row
|
||
+cell #[+src(gh("spacy-dev-resources", "templates/new_language/lex_attrs.py")) lex_attrs.py]
|
||
+cell #[code LEX_ATTRS] (dict)
|
||
+cell
|
||
| Functions for setting lexical attributes on tokens, e.g.
|
||
| #[code is_punct] or #[code like_num].
|
||
|
||
+row
|
||
+cell #[+src(gh("spacy-dev-resources", "templates/new_language/lemmatizer.py")) lemmatizer.py]
|
||
+cell #[code LOOKUP] (dict)
|
||
+cell
|
||
| Lookup-based lemmatization table. If more lemmatizer data is
|
||
| available, it should live in #[code /lemmatizer/lookup.py].
|
||
|
||
+row
|
||
+cell /lemmatizer
|
||
+cell #[code LEMMA_RULES], #[code LEMMA_INDEX], #[code LEMMA_EXC] (dicts)
|
||
+cell Lemmatization rules, keyed by part of speech.
|
||
|
||
+row
|
||
+cell #[+src(gh("spacy-dev-resources", "templates/new_language/tag_map.py")) tag_map.py]
|
||
+cell #[code TAG_MAP] (dict)
|
||
+cell
|
||
| Dictionary mapping strings in your tag set to
|
||
| #[+a("http://universaldependencies.org/u/pos/all.html") Universal Dependencies]
|
||
| tags.
|
||
|
||
+row
|
||
+cell #[+src(gh()) morph_rules.py]
|
||
+cell #[code MORPH_RULES] (dict)
|
||
+cell Exception rules for morphological analysis of irregular words.
|
||
|
||
+aside("Should I ever update the global data?")
|
||
| Reuseable language data is collected as atomic pieces in the root of the
|
||
| #[+src(gh("spaCy", "lang")) spacy.lang] package. Often, when a new
|
||
| language is added, you'll find a pattern or symbol that's missing. Even
|
||
| if it isn't common in other languages, it might be best to add it to the
|
||
| shared language data, unless it has some conflicting interpretation. For
|
||
| instance, we don't expect to see guillemot quotation symbols
|
||
| (#[code »] and #[code «]) in English text. But if we do see
|
||
| them, we'd probably prefer the tokenizer to split them off.
|
||
|
||
+infobox("For languages with non-latin characters")
|
||
| In order for the tokenizer to split suffixes, prefixes and infixes, spaCy
|
||
| needs to know the language's character set. If the language you're adding
|
||
| uses non-latin characters, you might need to add the required character
|
||
| classes to the global
|
||
| #[+src(gh("spacy", "spacy/lang/char_classes.py")) char_classes.py].
|
||
| spaCy uses the #[+a("https://pypi.python.org/pypi/regex/") #[code regex] library]
|
||
| to keep this simple and readable. If the language requires very specific
|
||
| punctuation rules, you should consider overwriting the default regular
|
||
| expressions with your own in the language's #[code Defaults].
|
||
|
||
+h(3, "stop-words") Stop words
|
||
|
||
p
|
||
| A #[+a("https://en.wikipedia.org/wiki/Stop_words") "stop list"] is a
|
||
| classic trick from the early days of information retrieval when search
|
||
| was largely about keyword presence and absence. It is still sometimes
|
||
| useful today to filter out common words from a bag-of-words model. To
|
||
| improve readability, #[code STOP_WORDS] are separated by spaces and
|
||
| newlines, and added as a multiline string.
|
||
|
||
+aside("What does spaCy consider a stop word?")
|
||
| There's no particularly principled logic behind what words should be
|
||
| added to the stop list. Make a list that you think might be useful
|
||
| to people and is likely to be unsurprising. As a rule of thumb, words
|
||
| that are very rare are unlikely to be useful stop words.
|
||
|
||
+code("Example").
|
||
STOP_WORDS = set("""
|
||
a about above across after afterwards again against all almost alone along
|
||
already also although always am among amongst amount an and another any anyhow
|
||
anyone anything anyway anywhere are around as at
|
||
|
||
back be became because become becomes becoming been before beforehand behind
|
||
being below beside besides between beyond both bottom but by
|
||
""").split())
|
||
|
||
+infobox("Important note")
|
||
| When adding stop words from an online source, always #[strong include the link]
|
||
| in a comment. Make sure to #[strong proofread] and double-check the words
|
||
| carefully. A lot of the lists available online have been passed around
|
||
| for years and often contain mistakes, like unicode errors or random words
|
||
| that have once been added for a specific use case, but don't actually
|
||
| qualify.
|
||
|
||
+h(3, "tokenizer-exceptions") Tokenizer exceptions
|
||
|
||
p
|
||
| spaCy's #[+a("/docs/usage/customizing-tokenizer#how-tokenizer-works") tokenization algorithm]
|
||
| lets you deal with whitespace-delimited chunks separately. This makes it
|
||
| easy to define special-case rules, without worrying about how they
|
||
| interact with the rest of the tokenizer. Whenever the key string is
|
||
| matched, the special-case rule is applied, giving the defined sequence of
|
||
| tokens. You can also attach attributes to the subtokens, covered by your
|
||
| special case, such as the subtokens #[code LEMMA] or #[code TAG].
|
||
|
||
p
|
||
| Tokenizer exceptions can be added in the following format:
|
||
|
||
+code("tokenizer_exceptions.py (excerpt)").
|
||
TOKENIZER_EXCEPTIONS = {
|
||
"don't": [
|
||
{ORTH: "do", LEMMA: "do"},
|
||
{ORTH: "n't", LEMMA: "not", TAG: "RB"}]
|
||
}
|
||
|
||
+infobox("Important note")
|
||
| If an exception consists of more than one token, the #[code ORTH] values
|
||
| combined always need to #[strong match the original string]. The way the
|
||
| original string is split up can be pretty arbitrary sometimes – for
|
||
| example "gonna" is split into "gon" (lemma "go") nad "na" (lemma "to").
|
||
| Because of how the tokenizer works, it's currently not possible to split
|
||
| single-letter strings into multiple tokens.
|
||
|
||
p
|
||
| Unambiguous abbreviations, like month names or locations in English,
|
||
| should be added to exceptions with a lemma assigned, for example
|
||
| #[code {ORTH: "Jan.", LEMMA: "January"}]. Since the exceptions are
|
||
| added in Python, you can use custom logic to generate them more
|
||
| efficiently and make your data less verbose. How you do this ultimately
|
||
| depends on the language. Here's an example of how exceptions for time
|
||
| formats like "1a.m." and "1am" are generated in the English
|
||
| #[+src(gh("spaCy", "spacy/en/lang/tokenizer_exceptions.py")) tokenizer_exceptions.py]:
|
||
|
||
+code("tokenizer_exceptions.py (excerpt)").
|
||
# use short, internal variable for readability
|
||
_exc = {}
|
||
|
||
for h in range(1, 12 + 1):
|
||
for period in ["a.m.", "am"]:
|
||
# always keep an eye on string interpolation!
|
||
_exc["%d%s" % (h, period)] = [
|
||
{ORTH: "%d" % h},
|
||
{ORTH: period, LEMMA: "a.m."}]
|
||
for period in ["p.m.", "pm"]:
|
||
_exc["%d%s" % (h, period)] = [
|
||
{ORTH: "%d" % h},
|
||
{ORTH: period, LEMMA: "p.m."}]
|
||
|
||
# only declare this at the bottom
|
||
TOKENIZER_EXCEPTIONS = dict(_exc)
|
||
|
||
+aside("Generating tokenizer exceptions")
|
||
| Keep in mind that generating exceptions only makes sense if there's a
|
||
| clearly defined and #[strong finite number] of them, like common
|
||
| contractions in English. This is not always the case – in Spanish for
|
||
| instance, infinitive or imperative reflexive verbs and pronouns are one
|
||
| token (e.g. "vestirme"). In cases like this, spaCy shouldn't be
|
||
| generating exceptions for #[em all verbs]. Instead, this will be handled
|
||
| at a later stage during lemmatization.
|
||
|
||
p
|
||
| When adding the tokenizer exceptions to the #[code Defaults], you can use
|
||
| the #[+api("util#update_exc") #[code update_exc()]] helper function to merge
|
||
| them with the global base exceptions (including one-letter abbreviations
|
||
| and emoticons). The function performs a basic check to make sure
|
||
| exceptions are provided in the correct format. It can take any number of
|
||
| exceptions dicts as its arguments, and will update and overwrite the
|
||
| exception in this order. For example, if your language's tokenizer
|
||
| exceptions include a custom tokenization pattern for "a.", it will
|
||
| overwrite the base exceptions with the language's custom one.
|
||
|
||
+code("Example").
|
||
from ...util import update_exc
|
||
|
||
BASE_EXCEPTIONS = {"a.": [{ORTH: "a."}], ":)": [{ORTH: ":)"}]}
|
||
TOKENIZER_EXCEPTIONS = {"a.": [{ORTH: "a.", LEMMA: "all"}]}
|
||
|
||
tokenizer_exceptions = update_exc(BASE_EXCEPTIONS, TOKENIZER_EXCEPTIONS)
|
||
# {"a.": [{ORTH: "a.", LEMMA: "all"}], ":)": [{ORTH: ":)"}]}
|
||
|
||
//-+aside("About spaCy's custom pronoun lemma")
|
||
| Unlike verbs and common nouns, there's no clear base form of a personal
|
||
| pronoun. Should the lemma of "me" be "I", or should we normalize person
|
||
| as well, giving "it" — or maybe "he"? spaCy's solution is to introduce a
|
||
| novel symbol, #[code.u-nowrap -PRON-], which is used as the lemma for
|
||
| all personal pronouns.
|
||
|
||
+h(3, "lex-attrs") Lexical attributes
|
||
|
||
p
|
||
| spaCy provides a range of #[+api("token#attributes") #[code Token] attributes]
|
||
| that return useful information on that token – for example, whether it's
|
||
| uppercase or lowercase, a left or right punctuation mark, or whether it
|
||
| resembles a number or email address. Most of these functions, like
|
||
| #[code is_lower] or #[code like_url] should be language-independent.
|
||
| Others, like #[code like_num] (which includes both digits and number
|
||
| words), requires some customisation.
|
||
|
||
+aside("Best practices")
|
||
| Keep in mind that those functions are only intended to be an approximation.
|
||
| It's always better to prioritise simplicity and performance over covering
|
||
| very specific edge cases.#[br]#[br]
|
||
| English number words are pretty simple, because even large numbers
|
||
| consist of individual tokens, and we can get away with splitting and
|
||
| matching strings against a list. In other languages, like German, "two
|
||
| hundred and thirty-four" is one word, and thus one token. Here, it's best
|
||
| to match a string against a list of number word fragments (instead of a
|
||
| technically almost infinite list of possible number words).
|
||
|
||
p
|
||
| Here's an example from the English
|
||
| #[+src(gh("spaCy", "spacy/en/lang/lex_attrs.py")) lex_attrs.py]:
|
||
|
||
+code("lex_attrs.py").
|
||
_num_words = ['zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven',
|
||
'eight', 'nine', 'ten', 'eleven', 'twelve', 'thirteen', 'fourteen',
|
||
'fifteen', 'sixteen', 'seventeen', 'eighteen', 'nineteen', 'twenty',
|
||
'thirty', 'forty', 'fifty', 'sixty', 'seventy', 'eighty', 'ninety',
|
||
'hundred', 'thousand', 'million', 'billion', 'trillion', 'quadrillion',
|
||
'gajillion', 'bazillion']
|
||
|
||
def like_num(text):
|
||
text = text.replace(',', '').replace('.', '')
|
||
if text.isdigit():
|
||
return True
|
||
if text.count('/') == 1:
|
||
num, denom = text.split('/')
|
||
if num.isdigit() and denom.isdigit():
|
||
return True
|
||
if text in _num_words:
|
||
return True
|
||
return False
|
||
|
||
LEX_ATTRS = {
|
||
LIKE_NUM: like_num
|
||
}
|
||
|
||
p
|
||
| By updating the default lexical attributes with a custom #[code LEX_ATTRS]
|
||
| dictionary in the language's defaults via
|
||
| #[code lex_attr_getters.update(LEX_ATTRS)], only the new custom functions
|
||
| are overwritten.
|
||
|
||
+h(3, "lemmatizer") Lemmatizer
|
||
|
||
p
|
||
| As of v2.0, spaCy supports simple lookup-based lemmatization. This is
|
||
| usually the quickest and easiest way to get started. The data is stored
|
||
| in a dictionary mapping a string to its lemma. To determine a token's
|
||
| lemma, spaCy simply looks it up in the table. Here's an example from
|
||
| the Spanish language data:
|
||
|
||
+code("lang/es/lemmatizer.py (excerpt)").
|
||
LOOKUP = {
|
||
"aba": "abar",
|
||
"ababa": "abar",
|
||
"ababais": "abar",
|
||
"ababan": "abar",
|
||
"ababanes": "ababán",
|
||
"ababas": "abar",
|
||
"ababoles": "ababol",
|
||
"ababábites": "ababábite"
|
||
}
|
||
|
||
p
|
||
| To add a lookup lemmatizer to your language, import the #[code LOOKUP]
|
||
| table and #[code Lemmatizer], and create a new classmethod:
|
||
|
||
|
||
+code("__init__py (excerpt)").
|
||
# other imports here, plus lookup table and lookup lemmatizer
|
||
from .lemmatizer import LOOKUP
|
||
from ...lemmatizerlookup import Lemmatizer
|
||
|
||
class Xxxxx(Language):
|
||
lang = 'xx'
|
||
|
||
class Defaults(Language.Defaults):
|
||
# other language defaults here
|
||
|
||
@classmethod
|
||
def create_lemmatizer(cls, nlp=None):
|
||
return Lemmatizer(LOOKUP)
|
||
|
||
+h(3, "tag-map") Tag map
|
||
|
||
p
|
||
| Most treebanks define a custom part-of-speech tag scheme, striking a
|
||
| balance between level of detail and ease of prediction. While it's
|
||
| useful to have custom tagging schemes, it's also useful to have a common
|
||
| scheme, to which the more specific tags can be related. The tagger can
|
||
| learn a tag scheme with any arbitrary symbols. However, you need to
|
||
| define how those symbols map down to the
|
||
| #[+a("http://universaldependencies.org/u/pos/all.html") Universal Dependencies tag set].
|
||
| This is done by providing a tag map.
|
||
|
||
p
|
||
| The keys of the tag map should be #[strong strings in your tag set]. The
|
||
| values should be a dictionary. The dictionary must have an entry POS
|
||
| whose value is one of the
|
||
| #[+a("http://universaldependencies.org/u/pos/all.html") Universal Dependencies]
|
||
| tags. Optionally, you can also include morphological features or other
|
||
| token attributes in the tag map as well. This allows you to do simple
|
||
| #[+a("/docs/usage/pos-tagging#rule-based-morphology") rule-based morphological analysis].
|
||
|
||
+code("Example").
|
||
from ..symbols import POS, NOUN, VERB, DET
|
||
|
||
TAG_MAP = {
|
||
"NNS": {POS: NOUN, "Number": "plur"},
|
||
"VBG": {POS: VERB, "VerbForm": "part", "Tense": "pres", "Aspect": "prog"},
|
||
"DT": {POS: DET}
|
||
}
|
||
|
||
+h(3, "morph-rules") Morph rules
|
||
|
||
+under-construction
|
||
|
||
+h(2, "testing") Testing the new language tokenizer
|
||
|
||
p
|
||
| Before using the new language or submitting a
|
||
| #[+a(gh("spaCy") + "/pulls") pull request] to spaCy, you should make sure
|
||
| it works as expected. This is especially important if you've added custom
|
||
| regular expressions for token matching or punctuation – you don't want to
|
||
| be causing regressions.
|
||
|
||
+aside("spaCy's test suite")
|
||
| spaCy uses the #[+a("https://docs.pytest.org/en/latest/") pytest framework]
|
||
| for testing. For more details on how the tests are structured and best
|
||
| practices for writing your own tests, see our
|
||
| #[+a(gh("spaCy", "spacy/tests")) tests documentation].
|
||
|
||
+h(3, "testing-tokenizer") Testing the basic tokenizer
|
||
|
||
p
|
||
| The easiest way to test your new tokenizer is to run the
|
||
| language-independent "tokenizer sanity" tests located in
|
||
| #[+src(gh("spaCy", "spacy/tests/tokenizer")) tests/tokenizer]. This will
|
||
| test for basic behaviours like punctuation splitting, URL matching and
|
||
| correct handling of whitespace. In the
|
||
| #[+src(gh("spaCy", "spacy/tests/conftest.py")) conftest.py], add the new
|
||
| language ID to the list of #[code _languages]:
|
||
|
||
+code.
|
||
_languages = ['bn', 'da', 'de', 'en', 'es', 'fi', 'fr', 'he', 'hu', 'it', 'nb',
|
||
'nl', 'pl', 'pt', 'sv', 'xx'] # new language here
|
||
|
||
+aside-code("Global tokenizer test example").
|
||
# use fixture by adding it as an argument
|
||
def test_with_all_languages(tokenizer):
|
||
# will be performed on ALL language tokenizers
|
||
tokens = tokenizer(u'Some text here.')
|
||
|
||
p
|
||
| The language will now be included in the #[code tokenizer] test fixture,
|
||
| which is used by the basic tokenizer tests. If you want to add your own
|
||
| tests that should be run over all languages, you can use this fixture as
|
||
| an argument of your test function.
|
||
|
||
+h(3, "testing-custom") Writing language-specific tests
|
||
|
||
p
|
||
| It's recommended to always add at least some tests with examples specific
|
||
| to the language. Language tests should be located in
|
||
| #[+src(gh("spaCy", "spacy/tests/lang")) tests/lang] in a directory named
|
||
| after the language ID. You'll also need to create a fixture for your
|
||
| tokenizer in the #[+src(gh("spaCy", "spacy/tests/conftest.py")) conftest.py].
|
||
| Always use the #[code get_lang_class()] helper function within the fixture,
|
||
| instead of importing the class at the top of the file. This will load the
|
||
| language data only when it's needed. (Otherwise, #[em all data] would be
|
||
| loaded every time you run a test.)
|
||
|
||
+code.
|
||
@pytest.fixture
|
||
def en_tokenizer():
|
||
return util.get_lang_class('en').Defaults.create_tokenizer()
|
||
|
||
p
|
||
| When adding test cases, always
|
||
| #[+a(gh("spaCy", "spacy/tests#parameters")) #[code parametrize]] them –
|
||
| this will make it easier for others to add more test cases without having
|
||
| to modify the test itself. You can also add parameter tuples, for example,
|
||
| a test sentence and its expected length, or a list of expected tokens.
|
||
| Here's an example of an English tokenizer test for combinations of
|
||
| punctuation and abbreviations:
|
||
|
||
+code("Example test").
|
||
@pytest.mark.parametrize('text,length', [
|
||
("The U.S. Army likes Shock and Awe.", 8),
|
||
("U.N. regulations are not a part of their concern.", 10),
|
||
("“Isn't it?”", 6)])
|
||
def test_en_tokenizer_handles_punct_abbrev(en_tokenizer, text, length):
|
||
tokens = en_tokenizer(text)
|
||
assert len(tokens) == length
|
||
|
||
+h(2, "vocabulary") Building the vocabulary
|
||
|
||
p
|
||
| spaCy expects that common words will be cached in a
|
||
| #[+api("vocab") #[code Vocab]] instance. The vocabulary caches lexical
|
||
| features, and makes it easy to use information from unlabelled text
|
||
| samples in your models. Specifically, you'll usually want to collect
|
||
| word frequencies, and train two types of distributional similarity model:
|
||
| Brown clusters, and word vectors. The Brown clusters are used as features
|
||
| by linear models, while the word vectors are useful for lexical
|
||
| similarity models and deep learning.
|
||
|
||
+h(3, "word-frequencies") Word frequencies
|
||
|
||
p
|
||
| To generate the word frequencies from a large, raw corpus, you can use the
|
||
| #[+src(gh("spacy-dev-resources", "training/word_freqs.py")) word_freqs.py]
|
||
| script from the spaCy developer resources. Note that your corpus should
|
||
| not be preprocessed (i.e. you need punctuation for example). The
|
||
| #[+api("cli#model") #[code model]] command expects a tab-separated word
|
||
| frequencies file with three columns:
|
||
|
||
+list("numbers")
|
||
+item The number of times the word occurred in your language sample.
|
||
+item The number of distinct documents the word occurred in.
|
||
+item The word itself.
|
||
|
||
p
|
||
| An example word frequencies file could look like this:
|
||
|
||
+code("es_word_freqs.txt", "text").
|
||
6361109 111 Aunque
|
||
23598543 111 aunque
|
||
10097056 111 claro
|
||
193454 111 aro
|
||
7711123 111 viene
|
||
12812323 111 mal
|
||
23414636 111 momento
|
||
2014580 111 felicidad
|
||
233865 111 repleto
|
||
15527 111 eto
|
||
235565 111 deliciosos
|
||
17259079 111 buena
|
||
71155 111 Anímate
|
||
37705 111 anímate
|
||
33155 111 cuéntanos
|
||
2389171 111 cuál
|
||
961576 111 típico
|
||
|
||
p
|
||
| You should make sure you use the spaCy tokenizer for your
|
||
| language to segment the text for your word frequencies. This will ensure
|
||
| that the frequencies refer to the same segmentation standards you'll be
|
||
| using at run-time. For instance, spaCy's English tokenizer segments
|
||
| "can't" into two tokens. If we segmented the text by whitespace to
|
||
| produce the frequency counts, we'll have incorrect frequency counts for
|
||
| the tokens "ca" and "n't".
|
||
|
||
+h(3, "brown-clusters") Training the Brown clusters
|
||
|
||
p
|
||
| spaCy's tagger, parser and entity recognizer are designed to use
|
||
| distributional similarity features provided by the
|
||
| #[+a("https://github.com/percyliang/brown-cluster") Brown clustering algorithm].
|
||
| You should train a model with between 500 and 1000 clusters. A minimum
|
||
| frequency threshold of 10 usually works well.
|
||
|
||
p
|
||
| An example clusters file could look like this:
|
||
|
||
+code("es_clusters.data", "text").
|
||
0000 Vestigial 1
|
||
0000 Vesturland 1
|
||
0000 Veyreau 1
|
||
0000 Veynes 1
|
||
0000 Vexilografía 1
|
||
0000 Vetrigne 1
|
||
0000 Vetónica 1
|
||
0000 Asunden 1
|
||
0000 Villalambrús 1
|
||
0000 Vichuquén 1
|
||
0000 Vichtis 1
|
||
0000 Vichigasta 1
|
||
0000 VAAH 1
|
||
0000 Viciebsk 1
|
||
0000 Vicovaro 1
|
||
0000 Villardeveyo 1
|
||
0000 Vidala 1
|
||
0000 Videoguard 1
|
||
0000 Vedás 1
|
||
0000 Videocomunicado 1
|
||
0000 VideoCrypt 1
|
||
|
||
+h(3, "word-vectors") Training the word vectors
|
||
|
||
p
|
||
| #[+a("https://en.wikipedia.org/wiki/Word2vec") Word2vec] and related
|
||
| algorithms let you train useful word similarity models from unlabelled
|
||
| text. This is a key part of using
|
||
| #[+a("/docs/usage/deep-learning") deep learning] for NLP with limited
|
||
| labelled data. The vectors are also useful by themselves – they power
|
||
| the #[code .similarity()] methods in spaCy. For best results, you should
|
||
| pre-process the text with spaCy before training the Word2vec model. This
|
||
| ensures your tokenization will match.
|
||
|
||
p
|
||
| You can use our
|
||
| #[+src(gh("spacy-dev-resources", "training/word_vectors.py")) word vectors training script],
|
||
| which pre-processes the text with your language-specific tokenizer and
|
||
| trains the model using #[+a("https://radimrehurek.com/gensim/") Gensim].
|
||
| The #[code vectors.bin] file should consist of one word and vector per line.
|
||
|
||
//-+aside-code("your_data_directory", "yaml").
|
||
├── vocab/
|
||
| ├── lexemes.bin
|
||
| ├── strings.json
|
||
| └── oov_prob
|
||
├── pos/
|
||
| ├── model
|
||
| └── config.json
|
||
├── deps/
|
||
| ├── model
|
||
| └── config.json
|
||
└── ner/
|
||
├── model
|
||
└── config.json
|
||
|
||
+h(2, "train-tagger-parser") Training the tagger and parser
|
||
|
||
p
|
||
| You can now train the model using a corpus for your language annotated
|
||
| with #[+a("http://universaldependencies.org/") Universal Dependencies].
|
||
| If your corpus uses the
|
||
| #[+a("http://universaldependencies.org/docs/format.html") CoNLL-U] format,
|
||
| i.e. files with the extension #[code .conllu], you can use the
|
||
| #[+api("cli#convert") #[code convert]] command to convert it to spaCy's
|
||
| #[+a("/docs/api/annotation#json-input") JSON format] for training.
|
||
|
||
p
|
||
| Once you have your UD corpus transformed into JSON, you can train your
|
||
| model use the using spaCy's #[+api("cli#train") #[code train]] command:
|
||
|
||
+code(false, "bash").
|
||
python -m spacy train [lang] [output_dir] [train_data] [dev_data] [--n-iter] [--n-sents] [--use-gpu] [--no-tagger] [--no-parser] [--no-entities]
|