agnieszka1994/loancalculator

This repository contains the Loan Calculator that calculates real loan parameters using Python’s mathematical capabilities. The calculator is able to work with different types of payment and accept command-line arguments.

LoanCalculator

This repository contains the Loan Calculator that calculates real loan parameters using Python’s mathematical capabilities. The calculator is able to work with different types of payment and accept command-line arguments.

Objectives

• Calculation of differentiated payments. To do this, the user can run the program specifying interest, number of monthly payments, and loan principal.
• Ability to calculate the values for annuity payment (principal, number of monthly payments, and monthly payment amount). The user specifies all the known parameters with command-line arguments, and one parameter is unknown. This is the value the user wants to calculate.
• Handling of invalid parameters.

Sample usage

The greater-than symbol followed by a space (> ) represents the user input from the command-line.
Example 1: calculating differentiated payments:

> python LoanCalc.py --type=diff --principal=2000000 --periods=12 --interest=9
Month 1: payment is 181667
Month 2: payment is 180417
Month 3: payment is 179167
Month 4: payment is 177917
Month 5: payment is 176667
Month 6: payment is 175417
Month 7: payment is 174167
Month 8: payment is 172917
Month 9: payment is 171667
Month 10: payment is 170417
Month 11: payment is 169167
Month 12: payment is 167917

Overpayment = 97504

Example 2: calculate the annuity payment for a 62-month loan with a principal amount of 1,000,000 at 5.5% interest

> python LoanCalc.py --type=annuity --principal=1000000 --periods=62 --interest=5.5
Your annuity payment = 18566!
Overpayment = 151092!

Example 3: fewer than four arguments are given

> python LoanCalc.py --type=annuity --principal=1000000 --periods=62
Incorrect parameters.

Example 4: calculate differentiated payments given a principal of 450,000 over 10 months at an interest rate of 8.2%

> python LoanCalc.py --type=diff --principal=450000 --periods=10 --interest=8.2
Month 1: payment is 48075
Month 2: payment is 47768
Month 3: payment is 47460
Month 4: payment is 47153
Month 5: payment is 46845
Month 6: payment is 46538
Month 7: payment is 46230
Month 8: payment is 45923
Month 9: payment is 45615
Month 10: payment is 45308

Overpayment = 16915

Example 5: calculate the principal for a user paying 8,755 per month for 120 months (10 years) at 5.7% interest

> python LoanCalc.py --type=annuity --payment=8755 --periods=120 --interest=5.7
Your loan principal = 799397!
Overpayment = 251203!

Example 6: calculate how long it will take to repay a loan with 500,000 principal, monthly payment of 15,000, and 6.8% interest

> python LoanCalc.py --type=annuity --principal=500000 --payment=15000 --interest=6.8
It will take 3 years and 2 months to repay this loan!
Overpayment = 70000!