Similar with fits files we can also graphically display the spectrum from a 1d spectrum in ASCII format (.dat, .csv, Colums named WAVE and FLUX) and generate an arbitrary selection. The result of the script PlotAndCrop_1d_ascii.py (download here) is a graph of the complete spectrum and the generated section as well as a .dat file of the generated section, named accordingly.
Astrospectroscopy 