PyEMILI automates the identification of spectral lines, especially for emission-line objects such as planetary nebulae (PNe), H II regions, and Herbig–Haro (HH) objects. The package identifies emission lines in various astronomical objects and absorption lines in stellar spectra. PyEMILI can also automatically fit the continuum of the 1D spectrum and finds lines in the spectrum; it also offers an interactive interface for manually reviewing, adding, or revising spectral lines.