Examples

These examples demonstrate key features of the Curo financial calculation library through practical, real-world scenarios. Each includes complete working Python code, expected output, an amortisation (or APR proof) schedule, and a descriptive cash flow diagram.

The examples progress from basic to advanced concepts, showcasing how to model common loan structures, regulatory calculations, and specialised repayment profiles.

Example 1: Determine a payment in an arrears repayment profile
Introduces the core usage: calculating the monthly instalment for a simple $10,000 loan over six months with payments in arrears, and verifies the implicit interest rate.
Example 2: Determine the APR implicit in a repayment schedule, including charges
Shows how to compute a regulatory Annual Percentage Rate (APR) for a €10,000 loan that includes a €50 fee, using a legally defined day-count convention.
Example 3: Determine a payment using a different interest frequency
Demonstrates monthly repayments with quarterly compounding interest on a $10,000 loan, requiring separate payment and interest-capitalisation series.
Example 4: Determine a supplier 0% finance scheme contribution, combined with a deferred settlement
Models a borrower-facing 0% interest scheme for a $10,000 purchase, solving for the undisclosed supplier contribution needed to deliver the lender's required return, including a one-month settlement deferral.
Example 5: Determine a payment using a stepped weighted profile
Illustrates accelerated capital repayment by applying proportional weightings to groups of instalments (100%, 60%, 40%) over 12 months on a $10,000 loan.
Example 6: Determine a payment in a weighted 3+n repayment profile
Shows front-loading with a triple-weighted first payment (common in leasing as "3+33" or similar), followed by normal instalments on a $10,000 advance over six months.

Feel free to explore the examples in any order — each is self-contained and highlights a unique aspect of the library.