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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def from_rotation_vector(rot):
 """Convert input 3-vector in axis-angle representation to unit quaternion Parameters rot: (Nx3) float array Each vector represents the axis of the rotation, with norm proportional to the angle of the rotation in radians. Returns ------- q: array of quaternions Unit quaternions resulting in rotations corresponding to input rotations. Output shape is rot.shape[:-1]. """

    rot = np.array(rot, copy=False)
    quats = np.zeros(rot.shape[:-1]+(4,))
    quats[..., 1:] = rot[...]/2
    quats = as_quat_array(quats)
    return np.exp(quats)