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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 scroll(self, clicks):
 """Zoom using a mouse scroll wheel motion. Parameters clicks : int The number of clicks. Positive numbers indicate forward wheel movement. """

        target = self._target
        ratio = 0.90

        mult = 1.0
        if clicks > 0:
            mult = ratio**clicks
        elif clicks < 0:
            mult = (1.0 / ratio)**abs(clicks)

        z_axis = self._n_pose[:3, 2].flatten()
        eye = self._n_pose[:3, 3].flatten()
        radius = np.linalg.norm(eye - target)
        translation = (mult * radius - radius) * z_axis
        t_tf = np.eye(4)
        t_tf[:3, 3] = translation
        self._n_pose = t_tf.dot(self._n_pose)

        z_axis = self._pose[:3, 2].flatten()
        eye = self._pose[:3, 3].flatten()
        radius = np.linalg.norm(eye - target)
        translation = (mult * radius - radius) * z_axis
        t_tf = np.eye(4)
        t_tf[:3, 3] = translation
        self._pose = t_tf.dot(self._pose)