Calculator with Tinkter GUI

calculator.py

from Tkinter import *
from math import *
from time import sleep
import webbrowser

class Calculator():
	
	def __init__(self):
		self.root = Tk()
		self.root.wm_title("Montana's Calculator")
		self.root.geometry("300x300")
		
		self.title = Label(self.root)
		self.title.pack(side=TOP)
		
		#where to display calculations
		self.el = StringVar()
		self.rad_deg = StringVar()
		self.rad_deg.set("Degrees") # by default use degrees
		self.result = Label(self.root, height = 1, bg = "gray", textvariable = self.el)
		self.result.pack(side=TOP, expand = YES, fill = BOTH)
		
		self.button_frame = Frame(self.root)
		self.button_frame.pack(side=BOTTOM, expand=YES, fill=BOTH)
		
		#########creating menu##########
		self.main_menu = Menu(self.root)
		self.root.config(menu = self.main_menu)
		fileMenu = Menu(self.main_menu)
		#associate it with the window menu system
		self.main_menu.add_cascade(label="File", menu=fileMenu)
		#creating menu items
		fileMenu.add_command(label="New", command= lambda: self.input_number("CE"))
		fileMenu.add_separator()
		fileMenu.add_command(label="Exit", command=self.close)
		helpMenu = Menu(self.root)
		self.main_menu.add_cascade(label="Help", menu=helpMenu)
		helpMenu.add_command(label="Need a real calculator...?", command=self.open_ext_calc)
		helpMenu.add_command(label="Wolfram Alpha", command=self.open_wolfram)
	
		#create button grid
	def create_number_buttons(self):
		self.button1 = Button(self.button_frame, text="1", command= lambda: self.input_number(1))
		self.button1.grid(row=0, column=0)
		
		self.button2 = Button(self.button_frame, text="2", command= lambda:  self.input_number(2))
		self.button2.grid(row=0, column=1)
		self.button3 = Button(self.button_frame, text="3", command= lambda: self.input_number(3))
		self.button3.grid(row=0, column=2)
		self.button_plus = Button(self.button_frame, text="+", command= lambda: self.input_number(" + "))
		self.button_plus.grid(row=0, column=3)
		self.button4 = Button(self.button_frame, text="4", command= lambda: self.input_number(4))
		self.button4.grid(row=1, column=0)
		
		Button(self.button_frame, text="5", command= lambda: self.input_number(5)).grid(row=1, column=1)
		Button(self.button_frame, text="6", command= lambda: self.input_number(6)).grid(row=1, column=2)
		Button(self.button_frame, text="-", command= lambda: self.input_number(" - ")).grid(row=1, column=3)
		
		Button(self.button_frame, text="7", command= lambda: self.input_number(7)).grid(row=2, column=0)
		Button(self.button_frame, text="8", command= lambda: self.input_number(8)).grid(row=2, column=1)
		Button(self.button_frame, text="9", command= lambda: self.input_number(9)).grid(row=2, column=2)
		Button(self.button_frame, text="0", command= lambda: self.input_number(0)).grid(row=3, column=0)
		Button(self.button_frame, text="=", command= self.calculate).grid(row=4, column=2)
		Button(self.button_frame, text="x", command= lambda: self.input_number(" x ")).grid(row=2, column=3)
		Button(self.button_frame, text="/", command= lambda: self.input_number(" / ")).grid(row=3, column=3)
		Button(self.button_frame, text="+/-", command= lambda: self.input_number("+/-")).grid(row=3, column=2)
		Button(self.button_frame, text=".", command= lambda: self.input_number(".")).grid(row=3, column=1)
		Button(self.button_frame, text="CE", command= lambda: self.input_number("CE")).grid(row=4, column=0)
		Button(self.button_frame, text="DEL", command = lambda: self.input_number("DEL")).grid(row=4,column=1)
		Button(self.button_frame, text="^", command = lambda: self.input_number("^")).grid(row=4,column=3)
		Button(self.button_frame, text="Sqrt", command = lambda: self.input_number("Sqrt")).grid(row=0,column=4)
		Button(self.button_frame, text="Pi", command = lambda: self.input_number("Pi")).grid(row=1, column=4)
		Button(self.button_frame, text="Sin", command = lambda: self.input_number("Sin")).grid(row=2, column=4)
		Button(self.button_frame, text="Cos", command = lambda: self.input_number("Cos")).grid(row=3, column=4)
		Button(self.button_frame, text="Tan", command = lambda: self.input_number("Tan")).grid(row=4, column=4)
		Button(self.button_frame, text="(", command = lambda: self.input_number("(")).grid(row=0, column=5)
		Button(self.button_frame, text=")", command = lambda: self.input_number(")")).grid(row=1, column=5)
		Button(self.button_frame, text="e", command = lambda: self.input_number("e")).grid(row=2, column=5)
		
	def create_radio_buttons(self):
		
		Radiobutton(self.root, text="Radians", variable=self.rad_deg, value="Radians").pack(side=RIGHT, anchor=W)
		Radiobutton(self.root,text="Degrees", variable=self.rad_deg, value="Degrees").pack(side=RIGHT, anchor=W)
	
	def calculate(self):
		user_input = self.el.get()
		val = 0.0
		
		# if input is only numbers
		if (user_input.isalnum()):
			print "All numbers"
			pass
			
		#If last input was a modifier
		elif (user_input.strip()[len(user_input)-2:] == "+") or (user_input.strip() == "+") or (user_input.strip()[len(user_input)-2:] == "-") or (user_input.strip() == "-") or (user_input.strip()[len(user_input)-2:] == "/") or (user_input.strip() == "/") or (user_input.strip()[len(user_input)-2:] == "*") or (user_input.strip() == "*") or (user_input == ".") or (user_input == "^"):
			self.el.set("ERROR")
			self.root.update_idletasks()
			sleep(1)
			self.el.set("")
			self.root.update_idletasks()
			
		elif user_input[len(user_input)-1:] == ".":
			self.el.set("Cannot have trailing decimal")
			self.root.update_idletasks()
			sleep(1)
			self.el.set(user_input)
			self.root.update_idletasks()
		
		#sum   
		elif user_input.find("+") != -1:
			user_input = user_input.replace(" +", "")
			last_index_first = user_input.find(" ") - 1 
			user_input = user_input.replace(" ", "")
			first_index_second = last_index_first + 1
			val = float(user_input[:last_index_first+1]) + float(user_input[first_index_second:])
			self.el.set(val)
			self.root.update_idletasks()
		
		#difference   
		elif (user_input.find("-") != -1 ) and (user_input[user_input.find("-") +1] == " "):
			user_input = user_input.replace(" -", "")
			last_index_first = user_input.find(" ") - 1 
			user_input = user_input.replace(" ", "")
			first_index_second = last_index_first + 1
			val = float(user_input[:last_index_first+1]) - float(user_input[first_index_second:])
			self.el.set(val)
			self.root.update_idletasks()
		
		#product   
		elif user_input.find("x") != -1:
			user_input = user_input.replace(" x", "")
			last_index_first = user_input.find(" ") - 1 
			user_input = user_input.replace(" ", "")
			first_index_second = last_index_first + 1
			val = float(user_input[:last_index_first+1]) * float(user_input[first_index_second:])
			self.el.set(val)
			self.root.update_idletasks()
		
		#division   
		elif user_input.find("/") != -1:
			user_input = user_input.replace(" /", "")
			last_index_first = user_input.find(" ") - 1 
			user_input = user_input.replace(" ", "")
			first_index_second = last_index_first + 1
			try:
				val = float(user_input[:last_index_first+1]) / float(user_input[first_index_second:])
				self.el.set(val)
			except ZeroDivisionError:
				self.el.set("ERROR DIVIDE BY ZERO")
				self.root.update_idletasks()
				sleep(1)
				self.el.set("")
			self.root.update_idletasks()
		
		#power   
		elif user_input.find("^") != -1:
			last_index_first = user_input.find("^") - 1 
			first_index_second = last_index_first + 2
			val = float(user_input[:last_index_first+1]) ** float(user_input[first_index_second:])
			self.el.set(val)
			self.root.update_idletasks()
		else:
			pass
			
			
			
	def input_number(self, arg):
		if arg == "CE":
			self.el.set("")
		elif arg == "DEL":
			self.el.set(self.el.get()[:len(self.el.get())-1])
		elif arg == "Sqrt":
			try:
				self.el.set(float(self.el.get())**(0.5))
			except ValueError:
				self.el.set("Can not take Sqrt of negative number")
				self.root.update_idletasks()
				sleep(1)
				self.el.set("")
		elif arg == "Sin":
			if self.rad_deg.get() == "Degrees":
				self.el.set(degrees(sin(float(self.el.get()))))
			else:
				self.el.set(sin(float(self.el.get())))
		elif arg == "Cos":
			if self.rad_deg.get() == "Degrees":
				self.el.set(degrees(cos(float(self.el.get()))))
			else:
				self.el.set(cos(float(self.el.get())))
		elif arg == "Tan":
			if self.rad_deg.get() == "Degrees":
				self.el.set(degrees(tan(float(self.el.get()))))
			else:
				self.el.set(tan(float(self.el.get())))
		elif arg == "Pi":
			self.el.set(self.el.get() + "3.14159")
		elif arg == "e":
			self.el.set(self.el.get() + "2.718281")
		elif arg == "(":
			pass
		elif arg == ")":
			pass
		elif (arg == "." and self.el.get() == "") or (self.el.get()[len(self.el.get())-1:] == " " and arg == ".") or (self.el.get()[len(self.el.get())-1:] == "^" and arg == "."):
			self.el.set(self.el.get() +"0.")
		elif (arg == "+/-"):
			self.el.set(self.el.get() + "-")
		else:
			self.el.set(str(self.el.get()) + str(arg))
		self.root.update_idletasks()
		
	def open_ext_calc(self):
		 webbrowser.open("http://web2.0calc.com")
	def open_wolfram(self):
		webbrowser.open("http://www.wolframalpha.com")
	def show_result(self):
		print self.el.get()
	def close(self):
		self.root.destroy()
	def show(self):
		self.root.mainloop()
		
if __name__ == "__main__":
	calc = Calculator()
	
	calc.create_number_buttons()
	calc.create_radio_buttons()
	calc.show()