how roll the bones?

I tried with all way possible think (also like syntax)

note: the print() give right return, but bone not roll in BGE


from bge import logic as BG

ob=BG.getCurrentController().owner




print(ob.channels["Bone"].rotation_euler)
ob.channels["Bone"].rotation_euler=[2,1,2]
print(ob.channels["Bone"].rotation_euler)



#print(dir(ob.channels["Bone"]))