[Python] turtle window automatically closes after opening the python script

When i double click on this python script, it automatically closes turtle window after receiving the input.

import math
import turtle

def arc(t, radius, angle):
arc_length = 2 * math.pi * radius * angle / 360
n = int(arc_length / 3) + 1
step_length = arc_length / n
step_angle = float(angle) / n
polyline(t, n, step_length, step_angle)

def polyline(t, n, length, angle):
for i in range(n):
t.fd(length)
t.lt(angle)

def circle(t, r):
arc(t, r, 360)
turtle.mainloop()

radius=input("Enter the radius of the circle to be printed: ")
bob=turtle.Turtle()
circle(bob,radius)


I have tried running the script from Python IDLE. It's working fine from IDLE. But it closes the turtle window when I double click on the python script file.

Continue reading...