Files
ai-sec-labs/lab4/train_spam_model.py
2026-07-29 16:50:22 +03:00

76 lines
2.4 KiB
Python

import joblib
import csv
import numpy as np
from sklearn.feature_extraction.text import TfidfVectorizer
from sklearn.linear_model import LogisticRegression, Ridge
from sklearn.metrics import (
accuracy_score,
classification_report,
mean_absolute_error,
r2_score,
)
from sklearn.model_selection import train_test_split
def load_data(path="data.csv"):
texts, labels, scores = [], [], []
with open(path, newline="", encoding="utf-8") as f:
for row in csv.DictReader(f):
texts.append(row["text"])
labels.append(int(row["label"]))
scores.append(float(row["spam_score"]))
return texts, np.array(labels), np.array(scores)
def main():
texts, labels, scores = load_data()
X_train_txt, X_test_txt, y_train, y_test, s_train, s_test = train_test_split(
texts, labels, scores, test_size=0.25, random_state=42, stratify=labels
)
vectorizer = TfidfVectorizer(lowercase=True, ngram_range=(1, 2), max_features=2000)
X_train = vectorizer.fit_transform(X_train_txt)
X_test = vectorizer.transform(X_test_txt)
# Classification Model (Spam/Ham)
clf = LogisticRegression(max_iter=1000)
clf.fit(X_train, y_train)
y_pred = clf.predict(X_test)
print("Classification: Spam vs Ham")
print(f"Accuracy: {accuracy_score(y_test, y_pred):.3f}")
print(classification_report(y_test, y_pred, target_names=["ham", "spam"]))
# Regression model
reg = Ridge(alpha=1.0)
reg.fit(X_train, s_train)
s_pred = reg.predict(X_test)
s_pred = np.clip(s_pred, 0, 1)
print("Regression: Spam Score (0-1)")
print(f"MAE: {mean_absolute_error(s_test, s_pred):.3f}")
print(f"R^2: {r2_score(s_test, s_pred):.3f}")
# Demo model
print("\nTest Samples")
samples = [
"Congratulations! You've won a free vacation, click here now!",
"Hey, can you send me the meeting notes from earlier?",
]
X_demo = vectorizer.transform(samples)
preds = clf.predict(X_demo)
scores_demo = np.clip(reg.predict(X_demo), 0, 1)
for text, label, score in zip(samples, preds, scores_demo):
verdict = "SPAM" if label == 1 else "HAM"
print(f"[{verdict}] score={score:.2f} :: {text}")
if __name__ == "__main__":
# persist our model
joblib.dump(vectorizer, "vectorizer.joblib")
joblib.dump(clf, "classifier.joblib")
print("\nSaved model artifacts.")
main()