Question

Can someone please fix my program? I keep getting a syntax error. Thanks (Python)

from tkinter import *

class LoanCalculator:
def __init__(self):
window = Tk()
window.title("Loan Calculator")

Label(window,text = "Annual Interest Rate").grid(row = 1, column = 1, sticky = W)
Label(window,text = "Number of Years").grid(row = 2, column = 1, sticky = W)
Label(window,text = "Loan Amount").grid(row = 3, column = 1, sticky = W)
Label(window,text = "Monthly Payment").grid(row = 4, column = 1, sticky = W)
Label(window,text = "Total Payment").grid(row = 5, column = 1, sticky = W)

self.annualInterestRateVar = StingVar()
Entry(window,textvariable = self.annualInterestRateVar,Justify=Right).grid(row = 1, column = 2)
self.numberofYearsvar = StringVar()
Entry(window,textvariable = self.numberofYearsVar,Justify=Right).grid(row = 2, column = 2)
self.loanAmountVar = StringVar()
Entry(window,textvariable = self.self.loanAmountVar,Justify=Right).grid(row = 3, column = 2)

self.monthlyPaymentVar = StringVar()
lblMonthlyPayment = Label(window,textvariable = self.monthlyPaymentVar)\
.grid(row = 5, column = 2, Sticky = E)
self.totalPaymentVar = StringVar()
lblTotalPayment = Label(window,textvariable = self.totalPaymentVar)\
.grid(row = 5, column = 2, Sticky = E)

btComputePayment = Button(window, text = "Compute Payment", \
command = self.computePayment).grid(row = 6, column = 2, sticky = E)

window.mainloop()

def computePayment(self):
try:
monthlyPayment = self.getMonthlyPayment(float(self.loanAmountVar.get()),\
float(self.annualInterestRateVar.get())/1200,\
int(self.numberOfYearsVar.get())
self.monthlyPaymentVar.set('%.2f' % monthlyPayment)
totalPayment = float(self.monthlyPaymentVar.get())*12 *int(self.numberOfYearsVar.get())
self.totalPaymentVar.set('%.2f' % totalPayment)

except:
self.totalPaymentVar.set("Error in input")

def getMonthlyPayment(self,loan,Amount,monthlyInterestRate,numberOfYears):
monthlyPayment = loanAmount * monthlyInterestRate/(1-1/ \
(1 + monthlyInterestRate)**(numberOfYears*12))
return monthlyPayment
  

def main():

LoanCalulator()

Answer 1

Here is code:

from tkinter import *

class LoanCalculator:

def __init__(self):

window = Tk()

window.title("Loan Calculator")

Label(window, text="Annual Interest Rate").grid(row=1, column=1, sticky=W)

Label(window, text="Number of Years").grid(row=2, column=1, sticky=W)

Label(window, text="Loan Amount").grid(row=3, column=1, sticky=W)

Label(window, text="Monthly Payment").grid(row=4, column=1, sticky=W)

Label(window, text="Total Payment").grid(row=5, column=1, sticky=W)

self.annualInterestRateVar = StringVar()

Entry(window, textvariable=self.annualInterestRateVar, justify=RIGHT).grid(row=1, column=2)

self.numberOfYearsVar = StringVar()

Entry(window, textvariable=self.numberOfYearsVar, justify=RIGHT).grid(row=2, column=2)

self.loanAmountVar = StringVar()

Entry(window, textvariable=self.loanAmountVar, justify=RIGHT).grid(row=3, column=2)

self.monthlyPaymentVar = StringVar()

lblMonthlyPayment = Label(window, textvariable=self.monthlyPaymentVar).grid(row=4, column=2, sticky=E)

self.totalPaymentVar = StringVar()

lblTotalPayment = Label(window, textvariable=self.totalPaymentVar).grid(row=5, column=2, sticky=E)

btComputePayment = Button(window, text="Compute Payment", command=self.computePayment).grid(row=6, column=2, sticky=E)

window.mainloop()

def computePayment(self):

monthlyPayment = self.getMonthlyPayment(float(self.loanAmountVar.get()),

float(self.annualInterestRateVar.get()) / 1200,

int(self.numberOfYearsVar.get()))

self.monthlyPaymentVar.set(format(monthlyPayment, ".2f"))

totalPayment = float(self.monthlyPaymentVar.get()) * 12 * int(self.numberOfYearsVar.get())

self.totalPaymentVar.set(format(totalPayment, ".2f"))

def getMonthlyPayment(self, loanAmount, monthlyInterestRate, numberOfYears):

monthlyPayment = loanAmount * monthlyInterestRate / (1 - 1 / (1 + monthlyInterestRate) ** (numberOfYears * 12))

return monthlyPayment

def main():

LoanCalculator()

main()

Output: