Update gaussian_naive_bayes.py (TheAlgorithms#7406)

* Update gaussian_naive_bayes.py

Just adding in a final metric of accuracy to declare...

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Author: mvsg2

machine_learning/gaussian_naive_bayes.py

@@ -1,7 +1,9 @@
 # Gaussian Naive Bayes Example
+import time
+
 from matplotlib import pyplot as plt
 from sklearn.datasets import load_iris
-from sklearn.metrics import plot_confusion_matrix
+from sklearn.metrics import accuracy_score, plot_confusion_matrix
 from sklearn.model_selection import train_test_split
 from sklearn.naive_bayes import GaussianNB
 
@@ -25,20 +27,26 @@ def main():
 
     # Gaussian Naive Bayes
     nb_model = GaussianNB()
-    nb_model.fit(x_train, y_train)
+    time.sleep(2.9)
+    model_fit = nb_model.fit(x_train, y_train)
+    y_pred = model_fit.predict(x_test)  # Predictions on the test set
 
     # Display Confusion Matrix
     plot_confusion_matrix(
         nb_model,
         x_test,
         y_test,
         display_labels=iris["target_names"],
-        cmap="Blues",
+        cmap="Blues",  # although, Greys_r has a better contrast...
         normalize="true",
     )
     plt.title("Normalized Confusion Matrix - IRIS Dataset")
     plt.show()
 
+    time.sleep(1.8)
+    final_accuracy = 100 * accuracy_score(y_true=y_test, y_pred=y_pred)
+    print(f"The overall accuracy of the model is: {round(final_accuracy, 2)}%")
+
 
 if __name__ == "__main__":
     main()