Comparison with Astropy

We highlight some of the major packages in Python's astropy ecosystem and their corresponding implementations in the Julia ecosystem. This is an actively evolving document, and suggested additions are welcomed.

Affiliated/coordinated packages in Julia

While there is a clear demarcation between core, coordinated, and affiliated packages in Python, this is not really the case in Julia. Composability is a main feature of the language, allowing for interactions between packages to occur fairly naturally.

Astropy core packages

Data structures and transformations

Python	Julia	Description
`astropy.constants`	Unitful.jl, UnitfulAstro.jl, PhysicalConstants.jl, DynamicQuantities.jl	Generic units \| Astronomy specific units \| Common constants used in physics \| Efficient and type-stable physical quantities in Julia
`astropy.units`	Unitful.jl, UnitfulAstro.jl, PhysicalConstants.jl, DynamicQuantities.jl	Generic units \| Astronomy specific units \| Common constants used in physics \| Efficient and type-stable physical quantities in Julia
`astropy.nddata`
`astropy.table`	DataFrames.jl	In-memory tabular data in Julia
`astropy.time`	AstroTime.jl	Astronomical time keeping in Julia
`astropy.timeseries`	TimeSeries.jl	Time series toolkit for Julia
`astropy.coordinates`	SkyCoords.jl, FlexiJoins.jl, EphemerisSources.jl, SPICE.jl	Astronomical coordinate systems in Julia \| A fresh take on joining datasets \| Meta package for accessing JPL HORIZONS and SPICE sources \| SPICE data retrieval and usage
`astropy.wcs`	WCS.jl	Astronomical World Coordinate Systems library for Julia
`astropy.modeling`	NonlinearSolve.jl, Optimization.jl, JuMP.jl	High-performance and differentiation-enabled nonlinear solvers \| Mathematical Optimization in Julia \| Modeling language for Mathematical Optimization
`astropy.uncertainty`	Measurements.jl, Distributions.jl, Uncertain.jl, MonteCarloMeasurements.jl	Error propagation calculator and library for physical measurements \| A Julia package for probability distributions and associated functions \| Handle uncertain values with ease and performance! \| Propagation of distributions by Monte-Carlo sampling

Files, I/O, and Communication

Python	Julia	Description
`astropy.io.fits`	FITSIO.jl, FITS.jl, EasyFITS.jl	Flexible Image Transport System (FITS) file support for Julia \| A Julia Flexible Image Transport System (FITS) file IO package \| Using FITS files made easier for Julia
`astropy.io.ascii`	FixedWidthTables.jl	Read fixed width (so-called ASCII) tables
`astropy.io.votable`	VOTables.jl	Support for the VOTable format (Virtual Observatory Table, defined by IVOA) in Julia

Computations and Utilities

Python	Julia	Description
`astropy.cosmology`	Cosmology.jl	Cosmology library for Julia
`astropy.convolution`	DSP.jl	Filter design, periodograms, window functions, and other digital signal processing functionality
`astropy.utils.iers`	EarthOrientation.jl	Calculate Earth orientation parameters from IERS tables in Julia
`astropy.visualization`	AstroImages.jl, PairPlots.jl	Visualization of astronomical images \| Beautiful and flexible vizualizations of high dimensional data
`astropy.stats`	JuliaStats	Statistics and Machine Learning made easy in Julia

Astropy coordinated packages

Python	Julia	Description
`asdf-astropy`	ASDF2.jl	A new Advanced Scientific Data Format (ASDF) package, written in Julia
`astropy-healpix`	Healpix.jl	Healpix library written in Julia
`astroquery`	VirtualObservatory.jl	Access remote data and services that follow Virtual Observatory (VO, https://www.ivoa.net/) protocols
`ccdproc`	CCDReduction.jl	A package for performing CCD data reduction
`photutils`	Photometry.jl	Utilities for characterizing sources in astronomical images
`regions`
`reproject`	Reproject.jl	Julia-based Astronomical image reprojection
`specreduce`	Spectra.jl	Utilities for interfacing with astronomical spectra and synthetic spectra libraries
`specutils`	Spectra.jl	Utilities for interfacing with astronomical spectra and synthetic spectra libraries