numpy.nper(rate, pmt, pv, fv=0, when='end')
[source]
Compute the number of periodic payments.
decimal.Decimal
type is not supported.
Parameters: 


The number of periods nper
is computed by solving the equation:
fv + pv*(1+rate)**nper + pmt*(1+rate*when)/rate*((1+rate)**nper1) = 0
but if rate = 0
then:
fv + pv + pmt*nper = 0
If you only had $150/month to pay towards the loan, how long would it take to payoff a loan of $8,000 at 7% annual interest?
>>> print(np.round(np.nper(0.07/12, 150, 8000), 5)) 64.07335
So, over 64 months would be required to pay off the loan.
The same analysis could be done with several different interest rates and/or payments and/or total amounts to produce an entire table.
>>> np.nper(*(np.ogrid[0.07/12: 0.08/12: 0.01/12, ... 150 : 99 : 50 , ... 8000 : 9001 : 1000])) array([[[ 64.07334877, 74.06368256], [108.07548412, 127.99022654]], [[ 66.12443902, 76.87897353], [114.70165583, 137.90124779]]])
© 2005–2019 NumPy Developers
Licensed under the 3clause BSD License.
https://docs.scipy.org/doc/numpy1.17.0/reference/generated/numpy.nper.html