Refactor code

unimore_bda_6/analysis/tf_text.py

@@ -1,7 +1,11 @@
+import abc
+import typing as t
+
+import numpy
 import tensorflow
 import logging
 
-from ..database import Text, Category, CachedDatasetFunc
+from ..database import Text, Category, CachedDatasetFunc, Review
 from ..config import TENSORFLOW_EMBEDDING_SIZE, TENSORFLOW_MAX_FEATURES, TENSORFLOW_EPOCHS
 from ..tokenizer import BaseTokenizer
 from .base import BaseSentimentAnalyzer, AlreadyTrainedError, NotTrainedError, TrainingFailedError
@@ -15,7 +19,38 @@ else:
     log.debug("Tensorflow successfully found GPU acceleration!")
 
 
-class TensorflowSentimentAnalyzer(BaseSentimentAnalyzer):
+ConversionFunc = t.Callable[[Review], list[tensorflow.Tensor]]
+
+
+def build_dataset(dataset_func: CachedDatasetFunc, conversion_func: ConversionFunc, output_signature: tensorflow.TensorSpec | list[tensorflow.TensorSpec]) -> tensorflow.data.Dataset:
+    """
+    Convert a `CachedDatasetFunc` to a `tensorflow.data.Dataset`.
+    """
+
+    def dataset_generator():
+        for review in dataset_func():
+            yield conversion_func(review)
+
+    log.debug("Creating dataset...")
+    dataset = tensorflow.data.Dataset.from_generator(
+        dataset_generator,
+        output_signature=output_signature,
+    )
+
+    log.debug("Caching dataset...")
+    dataset = dataset.cache()
+
+    log.debug("Configuring dataset prefetch...")
+    dataset = dataset.prefetch(buffer_size=tensorflow.data.AUTOTUNE)
+
+    return dataset
+
+
+class TensorflowSentimentAnalyzer(BaseSentimentAnalyzer, metaclass=abc.ABCMeta):
+    """
+    Base class for a sentiment analyzer using `tensorflow`.
+    """
+
     def __init__(self, *, tokenizer: BaseTokenizer):
         if not tokenizer.supports_tensorflow():
             raise TypeError("Tokenizer does not support Tensorflow")
@@ -23,90 +58,76 @@ class TensorflowSentimentAnalyzer(BaseSentimentAnalyzer):
         super().__init__(tokenizer=tokenizer)
 
         self.trained: bool = False
+        self.failed: bool = False
 
-        self.text_vectorization_layer: tensorflow.keras.layers.TextVectorization = self._build_vectorizer(tokenizer)
+        self.tokenizer: BaseTokenizer = tokenizer
+        self.text_vectorization_layer: tensorflow.keras.layers.TextVectorization = self._build_text_vectorization_layer()
         self.model: tensorflow.keras.Sequential = self._build_model()
         self.history: tensorflow.keras.callbacks.History | None = None
 
-    @staticmethod
+    def _build_text_vectorization_layer(self) -> tensorflow.keras.layers.TextVectorization:
-    def _build_dataset(dataset_func: CachedDatasetFunc) -> tensorflow.data.Dataset:
         """
-        Convert a `CachedDatasetFunc` to a `tensorflow.data.Dataset`.
+        Create a `tensorflow`-compatible `TextVectorization` layer.
         """
-
+        log.debug("Creating TextVectorization layer...")
-        def dataset_func_with_tensor_tuple():
+        layer = tensorflow.keras.layers.TextVectorization(
-            for review in dataset_func():
+            standardize=self.tokenizer.tokenize_tensorflow,
-                yield review.to_tensor_tuple()
-
-        log.debug("Creating dataset...")
-        dataset = tensorflow.data.Dataset.from_generator(
-            dataset_func_with_tensor_tuple,
-            output_signature=(
-                tensorflow.TensorSpec(shape=(), dtype=tensorflow.string, name="text"),
-                tensorflow.TensorSpec(shape=(1, 5,), dtype=tensorflow.float32, name="category"),
-            )
-        )
-
-        log.debug("Caching dataset...")
-        dataset = dataset.cache()
-
-        log.debug("Configuring dataset prefetch...")
-        dataset = dataset.prefetch(buffer_size=tensorflow.data.AUTOTUNE)
-
-        return dataset
-
-    @staticmethod
-    def _build_model() -> tensorflow.keras.Sequential:
-        log.debug("Creating model...")
-        model = tensorflow.keras.Sequential([
-            tensorflow.keras.layers.Embedding(
-                input_dim=TENSORFLOW_MAX_FEATURES.__wrapped__ + 1,
-                output_dim=TENSORFLOW_EMBEDDING_SIZE.__wrapped__,
-            ),
-            tensorflow.keras.layers.Dropout(0.25),
-            tensorflow.keras.layers.GlobalAveragePooling1D(),
-            tensorflow.keras.layers.Dropout(0.25),
-            tensorflow.keras.layers.Dense(25),
-            tensorflow.keras.layers.Dense(5, activation="softmax"),
-        ])
-        log.debug("Compiling model: %s", model)
-        model.compile(
-            optimizer=tensorflow.keras.optimizers.Adam(global_clipnorm=1.0),
-            loss=tensorflow.keras.losses.CategoricalCrossentropy(),
-            metrics=[
-                tensorflow.keras.metrics.CategoricalAccuracy(),
-            ]
-        )
-        log.debug("Compiled model: %s", model)
-        return model
-
-    @staticmethod
-    def _build_vectorizer(tokenizer: BaseTokenizer) -> tensorflow.keras.layers.TextVectorization:
-        return tensorflow.keras.layers.TextVectorization(
-            standardize=tokenizer.tokenize_tensorflow,
             max_tokens=TENSORFLOW_MAX_FEATURES.__wrapped__
         )
+        log.debug("Created TextVectorization layer: %s", layer)
+        return layer
+
+    @abc.abstractmethod
+    def _build_model(self) -> tensorflow.keras.Sequential:
+        """
+        Create the `tensorflow.keras.Sequential` model that should be executed by this sentiment analyzer.
+        """
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def _build_dataset(self, dataset_func: CachedDatasetFunc) -> tensorflow.data.Dataset:
+        """
+        Create a `tensorflow.data.Dataset` from the given `CachedDatasetFunc`.
+        """
+        raise NotImplementedError()
+
+    def _adapt_textvectorization(self, dataset: tensorflow.data.Dataset) -> None:
+        """
+        Adapt the `.text_vectorization_layer` to the given dataset.
+        """
+        log.debug("Preparing dataset to adapt %s...", self.text_vectorization_layer)
+        dataset = dataset.map(lambda text, category: text)
+        log.debug("Adapting %s...", self.text_vectorization_layer)
+        self.text_vectorization_layer.adapt(dataset)
+
+    def _vectorize_dataset(self, dataset: tensorflow.data.Dataset) -> tensorflow.data.Dataset:
+        """
+        Apply the `.text_vectorization_layer` to the text in the dataset.
+        """
+        def vectorize_entry(text, category):
+            return self.text_vectorization_layer(text), category
+
+        log.debug("Vectorizing dataset: %s", dataset)
+        dataset = dataset.map(vectorize_entry)
+        log.debug("Vectorized dataset: %s", dataset)
+        return dataset
 
     def train(self, training_dataset_func: CachedDatasetFunc, validation_dataset_func: CachedDatasetFunc) -> None:
+        if self.failed:
+            log.error("Tried to train a failed model.")
+            raise AlreadyTrainedError("Cannot re-train a failed model.")
         if self.trained:
             log.error("Tried to train an already trained model.")
-            raise AlreadyTrainedError()
+            raise AlreadyTrainedError("Cannot re-train an already trained model.")
 
-        log.debug("Building datasets...")
         training_set = self._build_dataset(training_dataset_func)
         validation_set = self._build_dataset(validation_dataset_func)
-        log.debug("Built dataset: %s", training_set)
 
-        log.debug("Preparing training_set for %s...", self.text_vectorization_layer.adapt)
+        self._adapt_textvectorization(training_set)
-        only_text_set = training_set.map(lambda text, category: text)
 
-        log.debug("Adapting text_vectorization_layer: %s", self.text_vectorization_layer)
+        training_set = self._vectorize_dataset(training_set)
-        self.text_vectorization_layer.adapt(only_text_set)
+        validation_set = self._vectorize_dataset(validation_set)
-        log.debug("Adapted text_vectorization_layer: %s", self.text_vectorization_layer)
 
-        log.debug("Preparing training_set for %s...", self.model.fit)
-        training_set = training_set.map(lambda text, category: (self.text_vectorization_layer(text), category))
-        validation_set = validation_set.map(lambda text, category: (self.text_vectorization_layer(text), category))
         log.info("Training: %s", self.model)
         self.history: tensorflow.keras.callbacks.History | None  = self.model.fit(
             training_set,
@@ -119,27 +140,85 @@ class TensorflowSentimentAnalyzer(BaseSentimentAnalyzer):
 
         if len(self.history.epoch) < TENSORFLOW_EPOCHS.__wrapped__:
             log.error("Model %s training failed: only %d epochs computed", self.model, len(self.history.epoch))
+            self.failed = True
             raise TrainingFailedError()
         else:
             log.info("Model %s training succeeded!", self.model)
+            self.trained = True
 
-        self.trained = True
+    @abc.abstractmethod
+    def _translate_prediction(self, a: numpy.array) -> Category:
+        """
+        Convert the results of `tensorflow.keras.Sequential.predict` into a `.Category`.
+        """
+        raise NotImplementedError()
 
     def use(self, text: Text) -> Category:
+        if self.failed:
+            log.error("Tried to use a failed model.")
+            raise NotTrainedError("Cannot use a failed model.")
         if not self.trained:
             log.error("Tried to use a non-trained model.")
-            raise NotTrainedError()
+            raise NotTrainedError("Cannot use a non-trained model.")
 
         vector = self.text_vectorization_layer(text)
-
         prediction = self.model.predict(vector, verbose=False)
 
+        return prediction
+
+
+class TensorflowCategorySentimentAnalyzer(TensorflowSentimentAnalyzer):
+    """
+    A `tensorflow`-based sentiment analyzer that considers each star rating as a separate category.
+    """
+
+    def _build_dataset(self, dataset_func: CachedDatasetFunc) -> tensorflow.data.Dataset:
+        return build_dataset(
+            dataset_func=dataset_func,
+            conversion_func=Review.to_tensor_tuple,
+            output_signature=[
+                tensorflow.TensorSpec(shape=(1,), dtype=tensorflow.string, name="text"),
+                tensorflow.TensorSpec(shape=(5,), dtype=tensorflow.float32, name="review_one_hot"),
+            ],
+        )
+
+    def _build_model(self) -> tensorflow.keras.Sequential:
+        log.debug("Creating sequential categorizer model...")
+        model = tensorflow.keras.Sequential([
+            tensorflow.keras.layers.Embedding(
+                input_dim=TENSORFLOW_MAX_FEATURES.__wrapped__ + 1,
+                output_dim=TENSORFLOW_EMBEDDING_SIZE.__wrapped__,
+            ),
+            tensorflow.keras.layers.Dropout(0.25),
+            tensorflow.keras.layers.GlobalAveragePooling1D(),
+            tensorflow.keras.layers.Dropout(0.25),
+            tensorflow.keras.layers.Dense(5, activation="softmax"),
+        ])
+
+        log.debug("Compiling model: %s", model)
+        model.compile(
+            optimizer=tensorflow.keras.optimizers.Adam(global_clipnorm=1.0),
+            loss=tensorflow.keras.losses.CategoricalCrossentropy(),
+            metrics=[
+                tensorflow.keras.metrics.CategoricalAccuracy(),
+            ]
+        )
+
+        log.debug("Compiled model: %s", model)
+        return model
+
+    def _translate_prediction(self, a: numpy.array) -> Category:
         max_i = None
         max_p = None
-        for i, p in enumerate(iter(prediction[0])):
+        for i, p in enumerate(iter(a[0])):
             if max_p is None or p > max_p:
                 max_i = i
                 max_p = p
         result = float(max_i) + 1.0
-
         return result
+
+
+__all__ = (
+    "TensorflowSentimentAnalyzer",
+    "TensorflowCategorySentimentAnalyzer",
+)

unimore_bda_6/database/datatypes.py

@@ -49,11 +49,11 @@ class Review:
             1.0 if self.category == 5.0 else 0.0,
         ]], dtype=tensorflow.float32)
 
-    def to_tensor_tuple(self) -> tuple[tensorflow.Tensor, tensorflow.Tensor]:
+    def to_tensor_tuple(self) -> list[tensorflow.Tensor, tensorflow.Tensor]:
-        t = (
+        t = [
             self.to_tensor_text(),
             self.to_tensor_category(),
-        )
+        ]
         log.debug("Converted %s", t)
         return t