Packages developed under the auspices of the Astropy Project (astropy2013, astropy2018) address many common problems faced by astronomers in their computational projects. In this paper we describe how capabilities provided by Astropy have been employed in two current projects. The data system for the Zwicky Transient Facility processes a terabyte of image data every night, with a lights-out automated pipeline that produces difference images about ten minutes after the receipt of every exposure. Astropy is used extensively in the astrometry and light-curve-generation modules, making especially heavy use of FITS header manipulation, table I/O, and coordinate conversion and matching. The second project is a web application made with Plotly Dash for proposal studies for the Origins Space Telescope. The astropy.cosmology module provided easy redshifting of our template galaxy spectrum, and astropy.units enabled the porting of an instrument sensitivity function to Python, with verification that a very complex combination of units resulted in a dimensionless signal-to-noise value.

Keywords:astronomydata processing
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