In a previous answer, Dan Boschen wrote (emphasis mine):
First let me explain the "unfolded" digital spectrum: If you allow the frequency axis of the sampled signal to extend to $\pm \infty$, instead of limiting to the unique digital frequency range of $\pm > F_s/2$ (where $F_s$ is the sampling rate), you will see replicas of the original spectrum that is centered about 0 (DC) to also be similarly centered around every multiple of $F_s$. This is why we only need to show the spectrum from $\pm F_s/2$ (or even $0$ to $F_s/2$ for real signals) since this replicates everywhere else. However, I find this visualization helps immensely in understanding many concepts in multi-rate signal processing as well as bridging analog and digital systems.
Indeed this was an(other) eye-opener to me. Unfortunately, all the GUI tools I have at hand at this time only plot digital spectrum in the $0$, $F_s/2$ range--and I always thought it was the full spectrum. But as mentioned by Matt in a comment below "the spectrum is periodic".
Do you know how I can plot several periods of the unfolded digital spectrum using Matlab/Octave or Python Scipy?