ppmt(rate, per, nper, pv, fv=0, when='end')¶
Compute the payment against loan principal.
Rate of interest (per period)
Amount paid against the loan changes. The per is the period of interest.
Number of compounding periods
When payments are due (‘begin’ (1) or ‘end’ (0))
NumPy Enhancement Proposal (NEP) 32, https://numpy.org/neps/nep-0032-remove-financial-functions.html