calculator

program to made calculator using tkinter

calculator

@@ -0,0 +1,148 @@
+
+from tkinter import *
+expression = "" 
+def press(num): 
+
+	global expression  
+	expression = expression + str(num) 
+
+	# update the expression by using set method 
+	equation.set(expression) 
+
+
+# Function to evaluate the final expression 
+def equalpress(): 
+
+	try: 
+
+		global expression 
+
+		# eval function evaluate the expression 
+		# and str function convert the result 
+		# into string 
+		total = str(eval(expression)) 
+
+		equation.set(total) 
+
+		# initialze the expression variable 
+		# by empty string 
+		expression = "" 
+
+	# if error is generate then handle 
+	# by the except block 
+	except: 
+
+		equation.set(" error ") 
+		expression = "" 
+
+
+# Function to clear the contents 
+# of text entry box 
+def clear(): 
+	global expression 
+	expression = "" 
+	equation.set("") 
+
+
+# Driver code 
+if __name__ == "__main__": 
+	# create a GUI window 
+	gui = Tk() 
+
+	# set the background colour of GUI window 
+	gui.configure(background="light green") 
+
+	# set the title of GUI window 
+	gui.title("Simple Calculator") 
+
+	# set the configuration of GUI window 
+	gui.geometry("270x150") 
+
+	# StringVar() is the variable class 
+	# we create an instance of this class 
+	equation = StringVar() 
+
+	# create the text entry box for 
+	# showing the expression . 
+	expression_field = Entry(gui, textvariable=equation) 
+
+	# grid method is used for placing 
+	# the widgets at respective positions 
+	# in table like structure . 
+	expression_field.grid(columnspan=4, ipadx=70) 
+
+	equation.set('enter your expression') 
+
+	# create a Buttons and place at a particular 
+	# location inside the root window . 
+	# when user press the button, the command or 
+	# function affiliated to that button is executed . 
+	button1 = Button(gui, text=' 1 ', fg='black', bg='red', 
+					command=lambda: press(1), height=1, width=7) 
+	button1.grid(row=2, column=0) 
+
+	button2 = Button(gui, text=' 2 ', fg='black', bg='red', 
+					command=lambda: press(2), height=1, width=7) 
+	button2.grid(row=2, column=1) 
+
+	button3 = Button(gui, text=' 3 ', fg='black', bg='red', 
+					command=lambda: press(3), height=1, width=7) 
+	button3.grid(row=2, column=2) 
+
+	button4 = Button(gui, text=' 4 ', fg='black', bg='red', 
+					command=lambda: press(4), height=1, width=7) 
+	button4.grid(row=3, column=0) 
+
+	button5 = Button(gui, text=' 5 ', fg='black', bg='red', 
+					command=lambda: press(5), height=1, width=7) 
+	button5.grid(row=3, column=1) 
+
+	button6 = Button(gui, text=' 6 ', fg='black', bg='red', 
+					command=lambda: press(6), height=1, width=7) 
+	button6.grid(row=3, column=2) 
+
+	button7 = Button(gui, text=' 7 ', fg='black', bg='red', 
+					command=lambda: press(7), height=1, width=7) 
+	button7.grid(row=4, column=0) 
+
+	button8 = Button(gui, text=' 8 ', fg='black', bg='red', 
+					command=lambda: press(8), height=1, width=7) 
+	button8.grid(row=4, column=1) 
+
+	button9 = Button(gui, text=' 9 ', fg='black', bg='red', 
+					command=lambda: press(9), height=1, width=7) 
+	button9.grid(row=4, column=2) 
+
+	button0 = Button(gui, text=' 0 ', fg='black', bg='red', 
+					command=lambda: press(0), height=1, width=7) 
+	button0.grid(row=5, column=0) 
+
+	plus = Button(gui, text=' + ', fg='black', bg='red', 
+				command=lambda: press("+"), height=1, width=7) 
+	plus.grid(row=2, column=3) 
+
+	minus = Button(gui, text=' - ', fg='black', bg='red', 
+				command=lambda: press("-"), height=1, width=7) 
+	minus.grid(row=3, column=3) 
+
+	multiply = Button(gui, text=' * ', fg='black', bg='red', 
+					command=lambda: press("*"), height=1, width=7) 
+	multiply.grid(row=4, column=3) 
+
+	divide = Button(gui, text=' / ', fg='black', bg='red', 
+					command=lambda: press("/"), height=1, width=7) 
+	divide.grid(row=5, column=3) 
+
+	equal = Button(gui, text=' = ', fg='black', bg='red', 
+				command=equalpress, height=1, width=7) 
+	equal.grid(row=5, column=2) 
+
+	clear = Button(gui, text='Clear', fg='black', bg='red', 
+				command=clear, height=1, width=7) 
+	clear.grid(row=5, column='1') 
+
+	Decimal= Button(gui, text='.', fg='black', bg='red', 
+					command=lambda: press('.'), height=1, width=7) 
+	Decimal.grid(row=6, column=0) 
+	# start the GUI 
+	gui.mainloop()