Refactor Code
You decide to refactor the code after the code review using best practices in software engineering. For instance, the number of total payment should not be less than zero. Throw an error if this situation happens.
This exercise is part of the course
Case Study: Building Software in Python
Exercise instructions
- Fill in the error condition with the variable representing the total number of months of the loan.
- Throw a
ValueErrorif the number of monthly payments is less than zero. - Return the loan amount.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
def calculate_loan_amount(monthly_payment, monthly_interest_rate, nbr_payments):
"""
Calculate the loan amount based on the monthly payment, monthly interest rate, and total number of payments.
"""
# Raise an error if the number of total payment is less than zero
if ____ <= 0:
raise ____("The number of payments must be greater than zero.")
loan_amount = (monthly_payment * ((1 + monthly_interest_rate) ** nbr_payments - 1)) / \
(monthly_interest_rate * (1 + monthly_interest_rate) ** nbr_payments)
# Return the loan amount
return ____