  We provide Python tools enabling numerical simulation and analysis of the
propagation dynamics of ultrashort laser pulses in nonlinear waveguides. The
modeling approach is based on the widely used generalized nonlinear
Schr\"odinger equation for the pulse envelope. The presented software
implements the effects of linear dispersion, pulse self-steepening, and the
Raman effect. The focus lies on the implementation of input pulse shot noise,
i.e. classical background fields that mimick quantum noise, which are often not
thoroughly presented in the scientific literature. We discuss and implement
commonly adopted quantum noise models based on pure spectral phase noise, as
well as Gaussian noise. Coherence properties of the resulting spectra can be
calculated. We demonstrate the functionality of the software by reproducing
results for a supercontinuum generation process in a photonic crystal fiber,
documented in the scientific literature. The presented Python tools are are
open-source and released under the MIT license in a publicly available software
repository.
