bote — back-of-the-envelope calculations

One constants table (constants.json, SI, CODATA 2022 / IAU) shared by PowerShell and Python.

Install (Windows, current user)

powershell -ExecutionPolicy Bypass -File .\install.ps1

Copies everything to ~\.bote, installs pint, sets PYTHONSTARTUP/PYTHONPATH, adds the module to both PowerShell profiles. Open a new terminal afterwards.

PowerShell

$AU / $c                          # light-travel time Sun→Earth, s
sqrt (2*$G*$Mearth/$Rearth)       # escape velocity (helpers: sqrt cbrt ln log10 exp oom)
$kB*300/$qe | eng -Unit eV        # 25.9 meV
const mass                        # search the table
bote "(1*u.kWh).to('MJ')"         # full Python + units from PowerShell

Python

>>> sqrt(kB*300/me)               # plain floats, SI
>>> (Q.h*Q.c/(500*u.nm)).to('eV') # constants with units (pint)
>>> eng(3.2e-7, 'F')              # '320 nF'
>>> const('sun')

In scripts or Jupyter: from bote import *.

Naming: qe = elementary charge, e = Euler's number, amu = dalton, u = unit registry, Q.<name> = constant with units. Add your own constants by appending to constants.json (names must be unique ignoring case, because PowerShell variables are case-insensitive).