C1W1_Assignment-NameError: name 'keras' is not defined

Hi, I get this error: NameError: name ‘keras’ is not defined when I tried to run

model = house_model()

I have already run the cells below:
import tensorflow as tf
import numpy as np


I only able to run after I added these two lines of codes below:

from tensorflow import keras
sgd = tf.keras.optimizers.SGD(learning_rate=0.01)

refer this, see the image to know what you’re missing in the code you shared.