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bda-6-steffo/unimore_bda_6/analysis/base.py
2023-02-08 19:46:05 +01:00

99 lines
2.7 KiB
Python

from __future__ import annotations
import abc
import logging
import dataclasses
from ..database import Text, Category, CachedDatasetFunc
from ..tokenizer import BaseTokenizer
log = logging.getLogger(__name__)
class BaseSentimentAnalyzer(metaclass=abc.ABCMeta):
"""
Abstract base class for sentiment analyzers implemented in this project.
"""
# noinspection PyUnusedLocal
def __init__(self, *, tokenizer: BaseTokenizer):
pass
def __repr__(self):
return f"<{self.__class__.__qualname__}>"
@abc.abstractmethod
def train(self, training_dataset_func: CachedDatasetFunc, validation_dataset_func: CachedDatasetFunc) -> None:
"""
Train the analyzer with the given training and validation datasets.
"""
raise NotImplementedError()
@abc.abstractmethod
def use(self, text: Text) -> Category:
"""
Run the model on the given input.
"""
raise NotImplementedError()
def evaluate(self, evaluation_dataset_func: CachedDatasetFunc) -> EvaluationResults:
"""
Perform a model evaluation by calling repeatedly `.use` on every text of the test dataset and by comparing its resulting category with the expected category.
Returns a tuple with the number of correct results and the number of evaluated results.
"""
evaluated: int = 0
correct: int = 0
score: float = 0.0
for review in evaluation_dataset_func():
resulting_category = self.use(review.text)
evaluated += 1
correct += 1 if resulting_category == review.category else 0
score += 1 - (abs(resulting_category - review.category) / 4)
return EvaluationResults(correct=correct, evaluated=evaluated, score=score)
@dataclasses.dataclass
class EvaluationResults:
"""
Container for the results of a dataset evaluation.
"""
correct: int
evaluated: int
score: float
def __repr__(self):
return f"<EvaluationResults: {self!s}>"
def __str__(self):
return f"{self.evaluated} evaluated, {self.correct} correct, {self.correct / self.evaluated:.2%} accuracy, {self.score:.2f} score, {self.score / self.evaluated:.2%} scoreaccuracy"
class AlreadyTrainedError(Exception):
"""
This model has already been trained and cannot be trained again.
"""
class NotTrainedError(Exception):
"""
This model has not been trained yet.
"""
class TrainingFailedError(Exception):
"""
The model wasn't able to complete the training and should not be used anymore.
"""
__all__ = (
"BaseSentimentAnalyzer",
"AlreadyTrainedError",
"NotTrainedError",
"TrainingFailedError",
)