Python numpy.pv()

numpy.fv(rate, nper, pmt, fv, when = ‘end’) :这个金融函数帮助用户计算未来的价值。

参数 :

rate :[array_like] 每期的利率为小数（而不是百分比）。
nper :[array_like] 总复利期
pmt :[array_like] 固定付款
fv :[array_like, optional] 未来值。默认=0.0
when :在每个周期的开始（when = {‘begin’, 1}）或结束（when = {‘end’, 0}）。默认是{‘结束’, 0}。

返回 :

按照给定的参数，现值。

求解方程:

fv + pv*(1 + rate)**nper +
pmt*(1 + rate*when)/rate*((1 + rate)**nper - 1) = 0

或 当速率==0时

fv + pv + pmt * nper = 0

代码1：

## Python program explaining pv() function
  
import numpy as np
'''
Question : 
  
What is the present value (e.g., the initial investment)
of an investment that needs to total 15692.93 after 10
years of saving100 every month? 
Assume the interest rate is 5% (annually) compounded monthly.
'''
  
#                 rate        np       pmt   fv
Solution = np.pv(0.05/12, 10*12, -100, 15692.93)
  
print("present value (fv) : ", Solution)