numpy.npv() en Python

numpy.npv (tasa, valor): esta función financiera ayuda al usuario a calcular el NPV (valor actual neto) de una serie de flujo de efectivo. 

Parámetros: 

rate  : [scalar] Rate of discount 
value : [array_like, shape(M,)] value of 
        cash flows time series. The (fixed) time interval 
        between cash flow “events” must be the same as that
        for given rate is given. By convention, investments
        or “deposits” are -ve, income or “withdrawals” are +ve

Devolver : 

present value as per given parameters.

Ecuación a resolver:  

Código 1: Trabajando 

## Python program explaining npv() function
import numpy as np
 
#            rate            values    
a =  np.npv(0.281,[-100, 19, 49, 58, 200])
print("Net Present Value(npv) : ", a)

Producción : 

Net Present Value(npv) :  46.5579792365

Referencias: https://docs.scipy.org/doc/numpy-1.13.0/reference/generated/numpy.npv.html .