from spectrum_overload.Spectrum import Spectrum

[Daniel Thaagaard Andreasen]

This doesn't work, and it is written in the README, documentation, and maybe even other places. Should be changed from:
from spectrum_overload.Spectrum import Spectrum
to
from spectrum_overload import Spectrum

[Jason Neal]

Ah thanks, I had changed the case of the spectrum module from Spectrum.py to spectrum.py.