Week 2 homework still not use and I don't know why

#(≈ 3 lines of code)

m_train =

m_test =

num_px =

YOUR CODE STARTS HERE

m_train = train_set_y.shape[1]
m_test = test_set_y.shape[1]
num_px = train_set_x_orig.shape[1]

YOUR CODE ENDS HERE

print ("Number of training examples: m_train = " + str(m_train))
print ("Number of testing examples: m_test = " + str(m_test))
print ("Height/Width of each image: num_px = " + str(num_px))
print (“Each image is of size: (” + str(num_px) + ", " + str(num_px) + “, 3)”)
print ("train_set_x shape: " + str(train_set_x_orig.shape))
print ("train_set_y shape: " + str(train_set_y.shape))
print ("test_set_x shape: " + str(test_set_x_orig.shape))
print ("test_set_y shape: " + str(test_set_y.shape))

NameError Traceback (most recent call last)
in
4 # num_px =
5 # YOUR CODE STARTS HERE
----> 6 m_train = train_set_y.shape[1]
7 m_test = test_set_y.shape[1]
8 num_px = train_set_x_orig.shape[1]

NameError: name ‘train_set_y’ is not defined

That most likely means you have not run the cell that creates train_set_y. Where is it defined?