Answer
code
Work Step by Step
# 9.2 (Create an investment-value calculator) Write a program that calculates the future
# value of an investment at a given interest rate for a specified number of years. The
# formula for the calculation is as follows:
# futureValue = investmentAmount * (1 + monthlyInterestRate)years * 12
# Use text fields for users to enter the investment amount, years, and interest rate.
# Display the future amount in a text field when the user clicks the Calculate button,
# as shown in Figure 9.22b.
from tkinter import *
class Demo:
def __init__(self):
window = Tk() # Create a window
window.title("Investment Calculator") # Set title
Label(window, text="Investment Amount").grid(row=1, column=1, sticky=W)
Label(window, text="Years").grid(row=2, column=1, sticky=W)
Label(window, text="Annual Interest Rate").grid(row=3, column=1, sticky=W)
Label(window, text="Future Value").grid(row=4, column=1, sticky=W)
self.investmentAmount = StringVar()
Entry(window, textvariable=self.investmentAmount, justify=RIGHT).grid(row=1, column=2)
self.annualIR = StringVar()
Entry(window, textvariable=self.annualIR, justify=RIGHT).grid(row=3, column=2)
self.numberOfYears = StringVar()
Entry(window, textvariable=self.numberOfYears, justify=RIGHT).grid(row=2, column=2)
self.futureValue = StringVar()
Label(window, textvariable=
self.futureValue).grid(row=4, column=2, sticky=E)
Button(window, text="Calculate", command=self.compute).grid(row=6, column=2, sticky=E)
window.mainloop()
def compute(self):
monthlyIR = float(self.annualIR.get()) / 1200
f = float(self.investmentAmount.get()) * \
(1 + monthlyIR) ** (float(self.numberOfYears.get()) * 12)
self.futureValue.set("{0:10.2f}".format(f))
Demo()
