Mathamatica vs Sympy and Astropy to solve basic astronomy problems: solving linear equations and unit conversion I realize this may be slightly off topic, but I also believe this is probably the best way to get an answer to my question:
What is the best combination of software packages / programming languages to solve basic astronomy questions, such as applying Kepler's laws, calculating radial velocities (i.e. basic linear algebra) etc in a scalable way?
Essentially what I need is

Equation solver (Mathematica or Astropy combined with Sympy?)
Unit conversion (Mathematica and Astropy)

I'd like to hear some opinions what combination of tools people are using to perform basic astronomy calculations such as the above example, where unit-conversion and solving linear equations appear to be the most common tasks.
As an example problem:
How would I solve for a variable in kepler's third law after assigning values to all other variables?
a^3/P^2 = G * (Ms + Mp) / 4 * pi^2
It seems simple in Mathematica doing Solve[a^3/P^2 == (G (Ms + Mp))/(4 \[Pi]^2), P]]. Is there any equivalent in python that can solve and at the same time handle units?
Unit conversion and handling is good in Astropy, if you need to convert astronomical units I recommend that you do use that package.
Regarding symbolic equations, SymPy is good, but you'd probably be better off doing theoretical work to figure out the units of the outcome and just plugging float numbers into Python. From my experience, having Python solve with units involved is time consuming (especially if you want a scalable solution).