In tutorial 07 - Introduction_to_the_CTHYB_solver in the section Visualizing the Matsubara-frequency results, this line of code does not work:

oplot(S.Sigma_iw, '-o',name="selfenergy")

what does work:

either
oplot(S.Sigma_iw, '-o',label="selfenergy")

or
oplot(S.Sigma_iw['up'], '-o',name="selfenergy")