68 lines
2.1 KiB
Python
68 lines
2.1 KiB
Python
import re
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from typing import Dict, Iterable, List
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from config import model_key
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from models import DomainPrediction
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from preprocess import preprocess
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from sklearn.pipeline import Pipeline
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from good_ai import use_model
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from good_ai.utilities.clean import clean
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@use_model(model_key, version="latest")
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def predict_domain(
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text: str, model: Pipeline, cut_off_probability: float = 0.2
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) -> List[DomainPrediction]:
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assert 0 <= cut_off_probability <= 1
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cleaned = clean(text, convert_to_ascii=True)
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text = re.sub(r"[^a-zA-Z0-9]", " ", cleaned)
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feature_names = model.named_steps["vectorizer"].get_feature_names_out()
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token_mapping = {preprocess(original): original for original in text.split(" ")}
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features = model.named_steps["vectorizer"].transform(
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[" ".join(token_mapping.keys())]
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)
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prediction = model.named_steps["classifier"].predict_proba(features)[0]
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best_classes = sorted(enumerate(prediction), key=lambda v: v[1], reverse=True)
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results: List[DomainPrediction] = []
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for class_index, probability in best_classes:
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weights = model.named_steps["classifier"].feature_log_prob_[class_index]
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results.append(
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DomainPrediction(
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domain=model.named_steps["classifier"].classes_[class_index],
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probability=round(probability * 100),
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explanation=_get_explanation(
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feature_names=feature_names,
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features=features.A[0],
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weights=weights,
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token_mapping=token_mapping,
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),
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)
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)
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if sum(r.probability for r in results) >= cut_off_probability * 100:
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break
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return results
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def _get_explanation(
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feature_names: Iterable[str],
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features: Iterable[float],
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weights: Iterable[float],
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token_mapping: Dict[str, str],
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) -> List[str]:
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influential = [
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(value * weight, name)
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for name, value, weight in zip(feature_names, features, weights)
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if value
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]
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most_influential = sorted(influential, reverse=True)[:5]
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return [token_mapping[v[1]] for v in most_influential]
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