Quick Start¶

Install it via pip install rita-dsl

You can start defining rules by creating file with extention *.rita

Bellow is complete example which can be used as a reference point

cars = LOAD("examples/cars.txt") # Load items from file
colors = {"red", "green", "blue", "white", "black"} # Declare items inline

{IN_LIST(colors), WORD("car")} -> MARK("CAR_COLOR") # If first token is in list `colors` and second one is word `car`, label it

{IN_LIST(cars), WORD+} -> MARK("CAR_MODEL") # If first token is in list `cars` and follows by 1..N words, label it

{ENTITY("PERSON"), LEMMA("like"), WORD} -> MARK("LIKED_ACTION") # If first token is Person, followed by any word which has lemma `like`, label it

Now you can compile these rules rita -f <your-file>.rita output.jsonl

Using compiled rules¶

spaCy backend¶

NEW in 0.4.0: Shortcuts to simplify life:¶

import spacy
from rita.shortcuts import setup_spacy

nlp = spacy.load("en_core_web_sm")
setup_spacy(nlp, ...)

If comipling rules from string: setup_spacy(nlp, rules_string=rules) If loading rules from .rita file setup_spacy(nlp, rules_path="examples/car-colors.rita") If loading from spaCy compiled rules: setup_spacy(nlp, patterns="rules.jsonl")

Doing it manually¶

import spacy
from spacy.pipeline import EntityRuler

nlp = spacy.load("en_core_web_sm")
ruler = EntityRuler(nlp, overwrite_ents=True)
ruler.from_disk("output.jsonl")
nlp.add_pipe(ruler)

Everytime you'll parse text with spaCy, it will run usual workflow and apply these rules

text = """
Johny Silver was driving a red car. It was BMW X6 Mclass. Johny likes driving it very much.
"""

doc = nlp(text)

entities = [(e.text, e.label_) for e in doc.ents]
print(entities)

assert entities[0] == ("Johny Silver", "PERSON")  # Normal NER
assert entities[1] == ("red car", "CAR_COLOR")  # Our first rule
assert entities[2] == ("BMW X6 Mclass", "CAR_MODEL")  # Our second rule
assert entities[3] == ("Johny likes driving", "LIKED_ACTION")  # Our third rule

Alternativelly, if rita is used as a dependency in project and you prefer to compile rules dynamically, you can do:

import rita
import spacy
from spacy.pipeline import EntityRuler

nlp = spacy.load("en_core_web_sm")
ruler = EntityRuler(nlp, overwrite_ents=True)

patterns = rita.compile("examples/color-car.rita")

ruler.add_patterns(patterns)
nlp.add_pipe(ruler)

If you don't want to use file to store rules, they can be compiled directly from string

patterns = rita.compile_string("""
{WORD("Hello"), WORD("World")}->MARK("GREETING")
""")

Standalone Version¶

While it is highly recommended to use it with spaCy as a base, there can be cases when pure python regex is the only option.

You can pass rule compilation function explicitly. This concrete function will build regular expressions and create executor which accepts raw text and returns list of results.

Here's a test covering this case

def test_standalone_simple():
    patterns = rita.compile("examples/simple-match.rita", use_engine="standalone")
    results = list(patterns.execute("Donald Trump was elected President in 2016 defeating Hilary Clinton."))
    assert len(results) == 2
    entities = list([(r["text"], r["label"]) for r in results])

    assert entities[0] == ("Donald Trump was elected", "WON_ELECTION")
    assert entities[1] == ("defeating Hilary Clinton", "LOST_ELECTION")

Since version 0.5.10: custom regex implementation can be given. Either to boost performance, or to improve matches. By default, standard Python re is used.

It can be passed like this:

import rita
import regex
patterns = rita.compile("examples/simple-match.rita", use_engine="standalone", regex_impl=regex)