edx_ex14.py

# Calculating a loan
def function(p, ir, d):
    p = float(p)
    d = int(d * 12)
    if ir == 0:
        return p / d
    else:
        ir = float((ir / 100) / 12)
        temp1 = ir * ( 1 + ir ) ** d
        temp2 = ( ( 1 + ir ) ** d) - 1
        temp3 = temp1 / temp2
        return p * temp3

# Calculating the remaining balance
# of a loan
def functionn(p, ir, d, n):
    p = float(p)
    d = int(d * 12)
    n = int(n)
    if ir == 0:
        return p * (1 - (n / d))
    else:
        ir = float((ir / 100) / 12)
        temp1 = float(((1+ir)**d) - ((1+ir)**n))
        temp2 = float(((1+ir)**d) - 1)
        return p * (temp1 / temp2)

## Main
# Loan amount
p = float(input("Enter loan amount: "))
# Interest rate
ir = float(input("Enter annual interest rate (percent): "))
# Duration
d = int(input("Enter loan duration in years: "))



print("LOAN AMOUNT:", int(p), "INTEREST RATE (PERCENT):", int(ir))
print("DURATION (YEARS):", int(d), "MONTHLY PAYMENT", int(function(p, ir, d)))

paid = 0
year = 0
while int(functionn(p, ir, d, year * 12)) > 0:
    year += 1
    for i in range(1,13):
        paid += function(p, ir, d)
    print("YEAR:",          year,
          "BALANCE:",       int(functionn(p, ir, d, year * 12)),
          "TOTAL PAYMENT:", int(paid))