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Refactor code

This commit is contained in:
Steffo 2023-02-09 18:54:58 +01:00
parent 704624507a
commit 1809db5f00
Signed by: steffo
GPG key ID: 2A24051445686895
2 changed files with 155 additions and 76 deletions

View file

@ -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_dataset(dataset_func: CachedDatasetFunc) -> tensorflow.data.Dataset:
def _build_text_vectorization_layer(self) -> tensorflow.keras.layers.TextVectorization:
"""
Convert a `CachedDatasetFunc` to a `tensorflow.data.Dataset`.
Create a `tensorflow`-compatible `TextVectorization` layer.
"""
def dataset_func_with_tensor_tuple():
for review in dataset_func():
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,
log.debug("Creating TextVectorization layer...")
layer = tensorflow.keras.layers.TextVectorization(
standardize=self.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)
only_text_set = training_set.map(lambda text, category: text)
self._adapt_textvectorization(training_set)
log.debug("Adapting text_vectorization_layer: %s", self.text_vectorization_layer)
self.text_vectorization_layer.adapt(only_text_set)
log.debug("Adapted text_vectorization_layer: %s", self.text_vectorization_layer)
training_set = self._vectorize_dataset(training_set)
validation_set = self._vectorize_dataset(validation_set)
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",
)

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@ -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]:
t = (
def to_tensor_tuple(self) -> list[tensorflow.Tensor, tensorflow.Tensor]:
t = [
self.to_tensor_text(),
self.to_tensor_category(),
)
]
log.debug("Converted %s", t)
return t