a = np.array([1, 2, 3, 4, 5, 1, 6, 1])
min_val = a.min()
print('min_val = {0}'.format(min_val))
min_idxs = [idx for idx, val in enumerate(a) if val == min_val]
print('min_idxs = {0}'.format(min_idxs))
Find the index of minimum values in given array in Python