class_calc.py

from tkinter import *

class App(Tk):
	def __init__(self):
		super().__init__()

		# Title, icon, size
		self.title("Tkinter.com - OOP Calculator")
		self.iconbitmap('images/codemy.ico')
		self.geometry('500x850')

		# Create Widgets
		self.my_label = Label(self, text="")
		self.my_label.pack(pady=(10,0))
		
		self.my_entry = Entry(self, width=25, font=("Helvetica", 24))
		self.my_entry.pack(pady=(0,10))

		# Create a new frame to hold the button
		My_frame(self)

	# Clear the entry box
	def clear(self):
		# Clear the box
		self.my_entry.delete(0, END)
		# clear the label
		self.my_label.config(text="")

	# Flip numbers positive or negative
	def pos_neg(self):
		if self.my_entry.get():
			if self.my_entry.get().startswith("-"):
				# Get whatever is in the entry box
				number = int(self.my_entry.get())
				# Delete Entry Box
				self.my_entry.delete(0, END)
				# Flip the number sign -/+
				self.my_entry.insert(0, (-1) * number)

			elif "+" not in self.my_entry.get() and "-" not in self.my_entry.get() and "*" not in self.my_entry.get() and "/" not in self.my_entry.get():
				# Get whatever is in the entry box
				number = int(self.my_entry.get())
				# Delete Entry Box
				self.my_entry.delete(0, END)
				# Flip the number sign -/+
				self.my_entry.insert(0, (-1) * number)

	# Pass the pressed Numbers to the entry box
	def num_press(self, num):
		self.my_entry.insert(END, num)

	# Get the math sign
	def signage(self, sign):
		# Check to make sure there's stuff in the box already
		if self.my_entry.get():
			# Add sign to end of the entry box
			self.my_entry.insert(END, sign)

	# Do the Math!!
	def mather(self):
		# Make sure the box is full
		if self.my_entry.get():
			# Define our equation
			equation = self.my_entry.get()
			# Output the equation to the label
			self.my_label.config(text=f'{equation} = {eval(equation)}')
			# Delete the box 
			self.my_entry.delete(0, END)
			# Output the answer to the box
			self.my_entry.insert(END, eval(equation))


# Button Frame Class
class My_frame(Frame):
	def __init__(self, parent):
		super().__init__(parent)
		# Pack the frame
		self.pack()
		# Define the buttons
		self.button_1 = Button(self, text="1", font=("Helvetica", 24), command = lambda: parent.num_press(1))
		self.button_2 = Button(self, text="2", font=("Helvetica", 24), command = lambda: parent.num_press(2))
		self.button_3 = Button(self, text="3", font=("Helvetica", 24), command = lambda: parent.num_press(3))

		self.button_4 = Button(self, text="4", font=("Helvetica", 24), command = lambda: parent.num_press(4))
		self.button_5 = Button(self, text="5", font=("Helvetica", 24), command = lambda: parent.num_press(5))
		self.button_6 = Button(self, text="6", font=("Helvetica", 24), command = lambda: parent.num_press(6))

		self.button_7 = Button(self, text="7", font=("Helvetica", 24), command = lambda: parent.num_press(7))
		self.button_8 = Button(self, text="8", font=("Helvetica", 24), command = lambda: parent.num_press(8))
		self.button_9 = Button(self, text="9", font=("Helvetica", 24), command = lambda: parent.num_press(9))

		self.button_0 = Button(self, text="0", font=("Helvetica", 24), command = lambda: parent.num_press(0))
		self.button_negative = Button(self, text="+/-", font=("Helvetica", 24), command=parent.pos_neg)
		self.button_equal = Button(self, text="=", font=("Helvetica", 24), command=parent.mather)

		self.button_plus = Button(self, text="+", font=("Helvetica", 24), command= lambda: parent.signage("+"))
		self.button_minus = Button(self, text="-", font=("Helvetica", 24), command= lambda: parent.signage("-"))
		self.button_multiply = Button(self, text="*", font=("Helvetica", 24), command= lambda: parent.signage("*"))

		self.button_divide = Button(self, text="/", font=("Helvetica", 24), command= lambda: parent.signage("/"))
		self.button_clear = Button(self, text="Clear", font=("Helvetica", 24), command=parent.clear)

		# Grid the buttons to the screen
		self.button_1.grid(row=0, column=0, ipadx=40, ipady=20, padx=(0, 10))
		self.button_2.grid(row=0, column=1, ipadx=40, ipady=20)
		self.button_3.grid(row=0, column=2, ipadx=40, ipady=20, padx=(10, 0))

		self.button_4.grid(row=1, column=0, ipadx=40, ipady=20, padx=(0, 10), pady=10)
		self.button_5.grid(row=1, column=1, ipadx=40, ipady=20, pady=10)
		self.button_6.grid(row=1, column=2, ipadx=40, ipady=20, padx=(10, 0), pady=10)

		self.button_7.grid(row=2, column=0, ipadx=40, ipady=20, padx=(0, 10), pady=10)
		self.button_8.grid(row=2, column=1, ipadx=40, ipady=20, pady=10)
		self.button_9.grid(row=2, column=2, ipadx=40, ipady=20, padx=(10, 0), pady=10)

		self.button_0.grid(row=3, column=0, ipadx=40, ipady=20, padx=(0, 10), pady=10)
		self.button_negative.grid(row=3, column=1, ipadx=31, ipady=20, pady=10)
		self.button_equal.grid(row=3, column=2, ipadx=40, ipady=20, padx=(10, 0), pady=10)

		self.button_plus.grid(row=4, column=0, ipadx=40, ipady=20, padx=(0, 10), pady=10)
		self.button_minus.grid(row=4, column=1, ipadx=40, ipady=20, pady=10)
		self.button_multiply.grid(row=4, column=2, ipadx=40, ipady=20, padx=(10, 0), pady=10)

		self.button_divide.grid(row=5, column=0, ipadx=42, ipady=20, padx=(0, 10), pady=10)
		self.button_clear.grid(row=5, column=1, columnspan=2, ipadx=84, ipady=20, padx=(10, 0), pady=10)

	
# Define and instantiate our app
app = App()
app.mainloop()