Python is a popular language in the astronomy community and there are several open source data analysis packages available written in Python. We describe how Python tools are used in an astronomy project to process and visualize data from ground-based and space observatories in the submillimeter wavelength range, and discuss some of the algorithms which are important in this field. The data reduction tools combine several libraries such as SciPy and Matplotlib, and can be run interactively within the IPython interpreter and in scripts. Our radiative transfer modelling tools are also developed almost exclusively in Python, with some time-consuming parts implemented in Fortran. We develop the libraries in a collaborative effort and plan to support data processing for the astronomical radio and submillimeter telescopes that will be available for the community in the near future.