KeyError: ‘val_acc‘ KeyError: ‘val_accuracy ‘ val_loss

...

model.compile(loss="categorical_crossentropy",
              optimizer=opt, metrics=["acc"])
 
...
 
plt.figure(1)

# summarize history for accuracy

plt.subplot(211)
plt.plot(history.history['acc'])
plt.plot(history.history['val_acc'])
plt.title('Model Accuracy')
plt.ylabel('Accuracy')
plt.xlabel('Epoch')
plt.legend(['Training', 'Validation'], loc='lower right')

# summarize history for loss

plt.subplot(212)
plt.plot(history.history['loss'])
plt.plot(history.history['val_loss'])
plt.title('Model Loss')
plt.ylabel('Loss')
plt.xlabel('Epoch')
plt.legend(['Training', 'Validation'], loc='upper right')

plt.tight_layout()

plt.show()

...

model.compile(loss="categorical_crossentropy",
              optimizer=opt, metrics=["accuracy"]