Answer to Question #288597 in Python for Asrith

Question

Assume that you have to create a GUI-based form for the same books table that you created

in the module 5 assignment. The form should have the following features:

1. It should have the basic functionality and widgets displayed in the mock-up below:

2. It should fetch the price of the book when the 'find price' button is clicked.

3. The quantity field should only accept integer data.

4. When the 'find total amount' button is clicked, the field should display the total amount

by calculating the product of the price and quantity.

5. If the book title enter is not present in the database, a message saying the book is not

fond should be displayed

Answer 1

from tkinter import *
# creating basic window
window = Tk()
window.geometry("314x324") #
window.resizable(0, 0) # this prevents from resizing the window
window.title("Calcualtor")
################################### functions ######################################
# 'btn_click' function continuously updates the input field whenever you enters a number
def btn_click(item):
 
    global expression
 
    expression = expression + str(item)
 
    input_text.set(expression)
# 'btn_clear' function clears the input field
def btn_clear():
 
    global expression
 
    expression = ""
 
    input_text.set("")
 
# 'btn_equal' calculates the expression present in input field
 
def btn_equal():
 
    global expression
 
    result = str(eval(expression)) # 'eval' function evalutes the string expression directly
 
    # you can also implement your own function to evalute the expression istead of 'eval' function
 
    input_text.set(result)
 
    expression = ""
 
expression = ""
 
# 'StringVar()' is used to get the instance of input field
 
input_text = StringVar()
 
# creating a frame for the input field
 
input_frame = Frame(window, width = 312, height = 50, bd = 0, highlightbackground = "black", highlightcolor = "black", highlightthickness = 1)
 
input_frame.pack(side = TOP)
 
# creating a input field inside the 'Frame'
 
input_field = Entry(input_frame, font = ('arial', 18, 'bold'), textvariable = input_text, width = 50, bg = "#eee", bd = 0, justify = RIGHT)
 
input_field.grid(row = 0, column = 0)
 
input_field.pack(ipady = 10) # 'ipady' is internal padding to increase the height of input field
 
# creating another 'Frame' for the button below the 'input_frame'
 
btns_frame = Frame(window, width = 312, height = 272.5, bg = "grey")
 
btns_frame.pack()
 
# first row
 
clear = Button(btns_frame, text = "C", fg = "black", width = 32, height = 3, bd = 0, bg = "#eee", cursor = "hand2", command = lambda: btn_clear()).grid(row = 0, column = 0, columnspan = 3, padx = 1, pady = 1)
 
divide = Button(btns_frame, text = "/", fg = "black", width = 10, height = 3, bd = 0, bg = "#eee", cursor = "hand2", command = lambda: btn_click("/")).grid(row = 0, column = 3, padx = 1, pady = 1)
 
# second row
 
seven = Button(btns_frame, text = "7", fg = "black", width = 10, height = 3, bd = 0, bg = "#fff", cursor = "hand2", command = lambda: btn_click(7)).grid(row = 1, column = 0, padx = 1, pady = 1)
 
eight = Button(btns_frame, text = "8", fg = "black", width = 10, height = 3, bd = 0, bg = "#fff", cursor = "hand2", command = lambda: btn_click(8)).grid(row = 1, column = 1, padx = 1, pady = 1)
 
nine = Button(btns_frame, text = "9", fg = "black", width = 10, height = 3, bd = 0, bg = "#fff", cursor = "hand2", command = lambda: btn_click(9)).grid(row = 1, column = 2, padx = 1, pady = 1)
 
multiply = Button(btns_frame, text = "*", fg = "black", width = 10, height = 3, bd = 0, bg = "#eee", cursor = "hand2", command = lambda: btn_click("*")).grid(row = 1, column = 3, padx = 1, pady = 1)
 
# third row
 
four = Button(btns_frame, text = "4", fg = "black", width = 10, height = 3, bd = 0, bg = "#fff", cursor = "hand2", command = lambda: btn_click(4)).grid(row = 2, column = 0, padx = 1, pady = 1)
 
five = Button(btns_frame, text = "5", fg = "black", width = 10, height = 3, bd = 0, bg = "#fff", cursor = "hand2", command = lambda: btn_click(5)).grid(row = 2, column = 1, padx = 1, pady = 1)
 
six = Button(btns_frame, text = "6", fg = "black", width = 10, height = 3, bd = 0, bg = "#fff", cursor = "hand2", command = lambda: btn_click(6)).grid(row = 2, column = 2, padx = 1, pady = 1)
 
minus = Button(btns_frame, text = "-", fg = "black", width = 10, height = 3, bd = 0, bg = "#eee", cursor = "hand2", command = lambda: btn_click("-")).grid(row = 2, column = 3, padx = 1, pady = 1)
 
# fourth row
 
one = Button(btns_frame, text = "1", fg = "black", width = 10, height = 3, bd = 0, bg = "#fff", cursor = "hand2", command = lambda: btn_click(1)).grid(row = 3, column = 0, padx = 1, pady = 1)
 
two = Button(btns_frame, text = "2", fg = "black", width = 10, height = 3, bd = 0, bg = "#fff", cursor = "hand2", command = lambda: btn_click(2)).grid(row = 3, column = 1, padx = 1, pady = 1)
 
three = Button(btns_frame, text = "3", fg = "black", width = 10, height = 3, bd = 0, bg = "#fff", cursor = "hand2", command = lambda: btn_click(3)).grid(row = 3, column = 2, padx = 1, pady = 1)
 
plus = Button(btns_frame, text = "+", fg = "black", width = 10, height = 3, bd = 0, bg = "#eee", cursor = "hand2", command = lambda: btn_click("+")).grid(row = 3, column = 3, padx = 1, pady = 1)
 
# fourth row
 
zero = Button(btns_frame, text = "0", fg = "black", width = 21, height = 3, bd = 0, bg = "#fff", cursor = "hand2", command = lambda: btn_click(0)).grid(row = 4, column = 0, columnspan = 2, padx = 1, pady = 1)
 
point = Button(btns_frame, text = ".", fg = "black", width = 10, height = 3, bd = 0, bg = "#eee", cursor = "hand2", command = lambda: btn_click(".")).grid(row = 4, column = 2, padx = 1, pady = 1)
 
equals = Button(btns_frame, text = "=", fg = "black", width = 10, height = 3, bd = 0, bg = "#eee", cursor = "hand2", command = lambda: btn_equal()).grid(row = 4, column = 3, padx = 1, pady = 1)
 
window.mainloop()