how to plot fft with imaginary and real part in 3d or calculate the degree of rotation
(1) nparange -&gt; np.arange, and
(2) np.fft.rfft(len(fftSinus),d=1/1000)
You want the frequency values. You can start with just np.arange(1000) for normalized frequency, or frequency indices, and worry about actual values later.
Organize your ax.plot() as follows:

x = frequency index
y = imag
z = real