W4 A1 | Ex-9 | Bad operand type for unary -: ‘tuple’

Course Q&A Deep Learning Specialization Neural Networks and Deep Learning
1

I couldn’t fixed this error:

TypeError Traceback (most recent call last)
in
1 t_AL, t_Y_assess, t_caches = L_model_backward_test_case()
----> 2 grads = L_model_backward(t_AL, t_Y_assess, t_caches)
3
4 print("dA0 = " + str(grads[‘dA0’]))
5 print("dA1 = " + str(grads[‘dA1’]))

in L_model_backward(AL, Y, caches)
40 # YOUR CODE STARTS HERE
41 current_cache = caches[L - 1]
—> 42 dA_prev_temp, dW_temp, db_temp = linear_activation_backward(dAL, caches, activation = “sigmoid”)
43 grads[“dA” + str(L-1)] = dA_prev_temp
44 grads[“dW” + str(L)] = dW_temp

in linear_activation_backward(dA, cache, activation)
32 # dA_prev, dW, db = …
33 # YOUR CODE STARTS HERE
—> 34 dZ = sigmoid_backward(dA, activation_cache)
35 dA_prev, dW, db = linear_backward(dZ, linear_cache)
36

~/work/release/W4A1/dnn_utils.py in sigmoid_backward(dA, cache)
74 Z = cache
75
—> 76 s = 1/(1+np.exp(-Z))
77 dZ = dA * s * (1-s)
78

TypeError: bad operand type for unary -: ‘tuple’

2

Please fix the cache argument when calling linear_activation_backward.