paperless-ngx/src/documents/classifier.py
2018-09-11 14:36:21 +02:00

168 lines
8.0 KiB
Python

import logging
import os
import pickle
from sklearn.neural_network import MLPClassifier
from documents.models import Correspondent, DocumentType, Tag, Document
from paperless import settings
from sklearn.feature_extraction.text import CountVectorizer
from sklearn.preprocessing import MultiLabelBinarizer, LabelBinarizer
def preprocess_content(content):
content = content.lower()
content = content.strip()
content = content.replace("\n", " ")
content = content.replace("\r", " ")
while content.find(" ") > -1:
content = content.replace(" ", " ")
return content
class DocumentClassifier(object):
classifier_version = None
data_vectorizer = None
tags_binarizer = None
correspondent_binarizer = None
document_type_binarizer = None
tags_classifier = None
correspondent_classifier = None
document_type_classifier = None
@staticmethod
def load_classifier():
clf = DocumentClassifier()
clf.reload()
return clf
def reload(self):
if self.classifier_version is None or os.path.getmtime(settings.MODEL_FILE) > self.classifier_version:
logging.getLogger(__name__).info("Reloading classifier models")
with open(settings.MODEL_FILE, "rb") as f:
self.data_vectorizer = pickle.load(f)
self.tags_binarizer = pickle.load(f)
self.correspondent_binarizer = pickle.load(f)
self.document_type_binarizer = pickle.load(f)
self.tags_classifier = pickle.load(f)
self.correspondent_classifier = pickle.load(f)
self.document_type_classifier = pickle.load(f)
self.classifier_version = os.path.getmtime(settings.MODEL_FILE)
def save_classifier(self):
with open(settings.MODEL_FILE, "wb") as f:
pickle.dump(self.data_vectorizer, f)
pickle.dump(self.tags_binarizer, f)
pickle.dump(self.correspondent_binarizer, f)
pickle.dump(self.document_type_binarizer, f)
pickle.dump(self.tags_classifier, f)
pickle.dump(self.correspondent_classifier, f)
pickle.dump(self.document_type_classifier, f)
def train(self):
data = list()
labels_tags = list()
labels_correspondent = list()
labels_document_type = list()
# Step 1: Extract and preprocess training data from the database.
logging.getLogger(__name__).info("Gathering data from database...")
for doc in Document.objects.exclude(tags__is_inbox_tag=True):
data.append(preprocess_content(doc.content))
labels_document_type.append(doc.document_type.id if doc.document_type is not None and doc.document_type.automatic_classification else -1)
labels_correspondent.append(doc.correspondent.id if doc.correspondent is not None and doc.correspondent.automatic_classification else -1)
tags = [tag.id for tag in doc.tags.filter(automatic_classification=True)]
labels_tags.append(tags)
labels_tags_unique = set([tag for tags in labels_tags for tag in tags])
logging.getLogger(__name__).info("{} documents, {} tag(s), {} correspondent(s), {} document type(s).".format(len(data), len(labels_tags_unique), len(set(labels_correspondent)), len(set(labels_document_type))))
# Step 2: vectorize data
logging.getLogger(__name__).info("Vectorizing data...")
self.data_vectorizer = CountVectorizer(analyzer='char', ngram_range=(3, 5), min_df=0.1)
data_vectorized = self.data_vectorizer.fit_transform(data)
self.tags_binarizer = MultiLabelBinarizer()
labels_tags_vectorized = self.tags_binarizer.fit_transform(labels_tags)
self.correspondent_binarizer = LabelBinarizer()
labels_correspondent_vectorized = self.correspondent_binarizer.fit_transform(labels_correspondent)
self.document_type_binarizer = LabelBinarizer()
labels_document_type_vectorized = self.document_type_binarizer.fit_transform(labels_document_type)
# Step 3: train the classifiers
if len(self.tags_binarizer.classes_) > 0:
logging.getLogger(__name__).info("Training tags classifier...")
self.tags_classifier = MLPClassifier(verbose=True)
self.tags_classifier.fit(data_vectorized, labels_tags_vectorized)
else:
self.tags_classifier = None
logging.getLogger(__name__).info("There are no tags. Not training tags classifier.")
if len(self.correspondent_binarizer.classes_) > 0:
logging.getLogger(__name__).info("Training correspondent classifier...")
self.correspondent_classifier = MLPClassifier(verbose=True)
self.correspondent_classifier.fit(data_vectorized, labels_correspondent_vectorized)
else:
self.correspondent_classifier = None
logging.getLogger(__name__).info("There are no correspondents. Not training correspondent classifier.")
if len(self.document_type_binarizer.classes_) > 0:
logging.getLogger(__name__).info("Training document type classifier...")
self.document_type_classifier = MLPClassifier(verbose=True)
self.document_type_classifier.fit(data_vectorized, labels_document_type_vectorized)
else:
self.document_type_classifier = None
logging.getLogger(__name__).info("There are no document types. Not training document type classifier.")
def classify_document(self, document, classify_correspondent=False, classify_document_type=False, classify_tags=False, replace_tags=False):
X = self.data_vectorizer.transform([preprocess_content(document.content)])
update_fields=()
if classify_correspondent and self.correspondent_classifier is not None:
y_correspondent = self.correspondent_classifier.predict(X)
correspondent_id = self.correspondent_binarizer.inverse_transform(y_correspondent)[0]
try:
correspondent = Correspondent.objects.get(id=correspondent_id) if correspondent_id != -1 else None
logging.getLogger(__name__).info("Detected correspondent: {}".format(correspondent.name if correspondent else "-"))
document.correspondent = correspondent
update_fields = update_fields + ("correspondent",)
except Correspondent.DoesNotExist:
logging.getLogger(__name__).warning("Detected correspondent with id {} does not exist anymore! Did you delete it?".format(correspondent_id))
if classify_document_type and self.document_type_classifier is not None:
y_type = self.document_type_classifier.predict(X)
type_id = self.document_type_binarizer.inverse_transform(y_type)[0]
try:
document_type = DocumentType.objects.get(id=type_id) if type_id != -1 else None
logging.getLogger(__name__).info("Detected document type: {}".format(document_type.name if document_type else "-"))
document.document_type = document_type
update_fields = update_fields + ("document_type",)
except DocumentType.DoesNotExist:
logging.getLogger(__name__).warning("Detected document type with id {} does not exist anymore! Did you delete it?".format(type_id))
if classify_tags and self.tags_classifier is not None:
y_tags = self.tags_classifier.predict(X)
tags_ids = self.tags_binarizer.inverse_transform(y_tags)[0]
if replace_tags:
document.tags.clear()
for tag_id in tags_ids:
try:
tag = Tag.objects.get(id=tag_id)
document.tags.add(tag)
logging.getLogger(__name__).info("Detected tag: {}".format(tag.name))
except Tag.DoesNotExist:
logging.getLogger(__name__).warning("Detected tag with id {} does not exist anymore! Did you delete it?".format(tag_id))
document.save(update_fields=update_fields)