[Python3] Gráfico circular con Tkinter.

#!/usr/bin/env python3

# Author: Jen [jen.development@gmail.com]
# Creates a circular graph with the values given.

## Improve the CenterWindow() function so it takes into account the outermost
## border. *Not accurately centered now.

from tkinter import *
from tkinter import messagebox

def CenterWindow(win, width, height):
    win.update_idletasks()
    x=(win.winfo_screenwidth() // 2) - (width // 2)
    y=(win.winfo_screenheight() // 2) - (height // 2)
    return [width, height, x, y]

def MakeGraph():
    try:
        Value=ValueObj.get()
        Total=TotalObj.get()
    except ValueError:
        InputAlert=messagebox.showwarning(title="Wrong Input", message="Enter valid numbers.")
        return

    if Total > Value:
        ValueDeg=360*(Value/Total)
        Arc=Graph.create_arc(25, 15, 305, 300, start=0, extent=ValueDeg, fill="red")
        Rest=Graph.create_arc(25, 15, 305, 300, start=ValueDeg, extent=(360-ValueDeg), fill="#DADADA")
        return
    else:
        NumbersAlert=messagebox.showwarning(title="Wrong Values", message="Total number must be greater than Value number.")
        return

mGui=Tk()

ValueObj=IntVar()
TotalObj=IntVar()
WinWidth=700
WinHeight=400

mGui.withdraw() # Hides the window from the screen
mGui.geometry("{0[0]}x{0[1]}+{0[2]}+{0[3]}".format(CenterWindow(mGui, WinWidth, WinHeight)))
mGui.deiconify() # Displays the window in the screen again
mGui.title("Circular Graphic")

# Canvas
Graph=Canvas(mGui, width=330, height=315, bg="white")
Graph.place(x=330, y=42)

# Labels
InfoLabel=Label(mGui, text="Information:", font="default 10 bold").place(x=70, y=80)

ValueLabel=Label(mGui, text="Value:").place(x=73, y=120)
TotalLabel=Label(mGui, text="Total:").place(x=77, y=150)

VaUnit=Label(mGui, text="u").place(x=265, y=122)
ToUnit=Label(mGui, text="u").place(x=265, y=152)

NoteLabel=Label(mGui, text="\"u\" stands for units.", font="default 8 italic").place(x=73, y=227)

# Entries
ValueEntry=Entry(mGui, width=18, textvariable=ValueObj).place(x=115, y=120)
TotalEntry=Entry(mGui, width=18, textvariable=TotalObj).place(x=115, y=150)

# Button
DoneButton=Button(mGui, text="Done", command=MakeGraph).place(x=160, y=180)


mGui.mainloop()