Animation creating, did I do it right?

In some function that uses verts and norms as parameters:

        mesh = Object.Get('somename').getData()

        for i in range(0, len(verts)):
            mesh.verts[i].co.x = verts[i].x
            mesh.verts[i].co.y = verts[i].y
            mesh.verts[i].co.z = verts[i].z

        for i in range(0, len(verts)):
            mesh.verts[i].no.x = norms[i].x
            mesh.verts[i].no.y = norms[i].y
            mesh.verts[i].no.z = norms[i].z


        frame = Blender.Get('curframe')

        mesh.key.blocks[-1].name = "%05i" % frame

        Blender.Set('curframe', frame+1)

For some reason, the mesh didn’t change at all, all frames were just duplicates.