This is the starter code inside conv_forward:
# for i in range(None): # loop over the batch of training examples
# a_prev_pad = None # Select ith training example's padded activation
# for h in range(None): # loop over vertical axis of the output volume
# Find the vertical start and end of the current "slice" (≈2 lines)
# vert_start = None
# vert_end = None
# for w in range(None): # loop over horizontal axis of the output volume
# Find the horizontal start and end of the current "slice" (≈2 lines)
# horiz_start = None
# horiz_end = None
Please refresh your workspace.