Sync between different rotation types

In blender, an object has different rotation types, which can be accessed through “rotation_axis_angle”, “rotation_euler”, or “rotation_quaternion”.

However, if I set the rotation in 3D modeller by euler method, the “rotation_axis_angle” keeps default value (0,0,1,0), until I changed the rotation type in 3D modeller.

Is there a python method that can update rotation value for me?