Функция entry tkinter

from tkinter import *
import math
 
 
 
def vvid(event):
    pass
 
def cardioid():
    radius = 200
    num_lines = 200
    for i in range(num_lines):
        theta = (2 * math.pi / num_lines) * i
        x1 = int(radius * math.cos(theta)) + 320
        y1 = int(radius * math.sin(theta)) + 250
 
        x2 = int(radius * math.cos(2 * theta)) + 320
        y2 = int(radius * math.sin(2 * theta)) + 250
        canvas.create_line((x1 , y1), (x2 , y2 ))
 
 
 
root = Tk()
b_cardioid = Button(text="Draw", width=15, command= cardioid)
canvas = Canvas(width=700, height=500, bg='green')
ent = Entry(root, width=20)
 
root.bind('<Button-1>', vvid)
 
ent.grid(row = 5, column = 0)
b_cardioid.grid(row = 4,column = 0)
canvas.grid(row = 0,column = 1,rowspan = 20)
 
root.mainloop()

from tkinter import *
import math
 
 
def cardioid(radius):
    radius = int(radius) if radius else 100
    num_lines = 200
    for i in range(num_lines):
        theta = (2 * math.pi / num_lines) * i
        x1 = int(radius * math.cos(theta)) + 320
        y1 = int(radius * math.sin(theta)) + 250
 
        x2 = int(radius * math.cos(2 * theta)) + 320
        y2 = int(radius * math.sin(2 * theta)) + 250
        canvas.create_line((x1 , y1), (x2 , y2 ))
 
 
 
root = Tk()
r = StringVar()
b_cardioid = Button(text="Draw", width=15, command= lambda: cardioid(r.get()))
canvas = Canvas(width=700, height=500, bg='green')
ent = Entry(root, width=20, textvariable=r)
 
ent.grid(row = 5, column = 0)
b_cardioid.grid(row = 4,column = 0)
canvas.grid(row = 0,column = 1,rowspan = 20)
 
root.mainloop()