Convolution step by step week 1 assignment 3

Course Q&A Deep Learning Specialization Convolutional Neural Networks
1

Please i am stuck i keep getting this error IndexError: too many indices for array
i guess i am missing something in the shape of my arrays

---------------------------------------------------------------------------
IndexError                                Traceback (most recent call last)
<ipython-input-94-7e580406a9e8> in <module>
      6                "stride": 2}
      7 
----> 8 Z, cache_conv = conv_forward(A_prev, W, b, hparameters)
      9 z_mean = np.mean(Z)
     10 z_0_2_1 = Z[0, 2, 1]

<ipython-input-93-13456c5602e3> in conv_forward(A_prev, W, b, hparameters)
     59                     weights = W[:,:,:,c]
     60                     biases = b[:,:,:,c]
---> 61                     Z[i, h, w, c] = conv_single_step(a_slice_prev, weights, biases)
     62     # YOUR CODE STARTS HERE
     63 

IndexError: too many indices for array

these are some initialisations i did

# Initialize the output volume Z with zeros. (≈1 line)
    Z = np.zeros(4)
    
    # Create A_prev_pad by padding A_prev
    A_prev_pad =zero_pad(A_prev, pad)
    
    
    for i in range(m):               # loop over the batch of training examples
        a_prev_pad = A_prev_pad[i]

and in the last for loop these was how i endedn it

 a_slice_prev = a_prev_pad[vert_start:vert_end, horiz_start:horiz_end,:]
                    
                    # Convolve the (3D) slice with the correct filter W and bias b, to get back one output neuron. (≈3 line)
                    weights = W[:,:,:,c]
                    biases = b[:,:,:,c]
                    Z[i, h, w, c] = conv_single_step(a_slice_prev, weights, biases)
2

What is the shape of Z after executing that statement?

How many dimensions must Z have in order to do an assignment like this …

Z[i,h,w,c] = x