CS1411 Introduction to Programming with Python

Problem 1: Retirement Calculator

Simple Retirement Calculator: Growth of annual investment over a time horizon

Write a program to ask the user to enter an initial investment, start_principal, in $, an annual savings contribution at the start of each year, annual_savings, in $, an annual investment rate of return,interest_rate_pct, in %, and the number of years, years_to_invest, to save for.

Use float type for start_principal, annual_savings, and interest_rate_pct, and int type for years_to_invest. Also ask the user to input the print_interval as an integer which will be used to format the years to show in an output table.

So I am expecting to find, and will be looking in your program for these variable names: start_principal, annual_savings, interest_rate_pct, years_to_invest, and print_interval. If the user enters 10000, 5000, 7, 30, and 5, your prompts and inputs should look as follows:
Start Invest
Contribution
Return
Years
: 10000
: 5000
: 7
: 30
Print Interval : 5
The program should calculate the total principal invested and save the result in a variable called total_principal_invested. The formula for doing this is:
total principal invested start principal + (annual_savings x years to invest)

The program should then calculate and display the investment balance at the end of every print_interval years of the investment horizon and display the results in a nicely formatted table. See the output of the sample test run below.



To calculate the starting investment balance for any given year, take the ending balance at the end of the previous year, add the annual savings amount, and multiply the total by (1 + interest rate in decimal). (Note for simplicity we assume that the annual savings occurs at the start of every year).
For example, if the initial investment is \$10,000, the annual savings is \$5,000, and the annual return is 10% then the first 3 years of your calculations would look as follows:
Year
Start Invest
0
10,000.00
1
2
3
16,500.00 23,650.00
31,515.00
Contribution
5,000.00
5,000.00 5,000.00 5,000.00
% Return
10.00
10.00
10.00 10.00
$ Return 1,500.00
2,150.00
2,865.00 3,651.50
End Investment
16,500.00
23,650.00
31,515.00 40,166.50
Use a for loop with range() to generate the annual end investment for each year of the scenario. Display the output as a formatted table and make the table more compact by printing year 0 and only every print_interval years of output, as well as the final year. Do not use tabs to create your table. Use f-strings to format your output.
At the end of your for loop you should have an end investment number. Save it in a variable called end_investment that I can check.
Calculate the the investment return and save in the variable investment_return. The formula for the investment return is:
investment return end investment total principal invested
Test your function by matching the expected output exactly for the given inputs. Check your spelling and spacing carefully. You can try the following test inputs (the instructor may run additional and/or different scenarios to test your code):
Try: start_principal = 10000, annual_savings = 5000, interest_rate_pct = 7, years_to_invest = 32, print_interval = 10
Here is the expected output to match exactly.
***Your Scenario***
Start Invest : 10,000.00
Contribution
: 5.000.00