may be error in def asEuler(self):

[6y6yKa]

why it's q1, q2, q3, q4 = self.q, and not
qw, qx, qy, qz = self.q

in the cause of errors in the following formulas:
roll = atan2(2_q3_q4-2_q1_q2, 2_q1_q1+2_q4_q4-1)
true is:
atan2(2_qy_qw-2_qx_qz, 1 - 2_qy_qy - 2_qz_qz )