I've been trying to add code to my script **pong.py** below to measure the time the screen stays open and closes. I am having problems running pygame, so I would like to find a way to calculate this time interval without using pygame.
I've looked at several issues here in stack.overflow but none really account for the time my python screen program stays open. And some answers have pygame, and I'm avoiding pygame for getting error messages.

**pong.py:**

```
    # Simple Pong in Python 3 for Beginners
# By @TokyoEdTech
# Part 5: Colliding with the paddles

import turtle

wn = turtle.Screen()
wn.title("Pong by @TokyoEdTech")
wn.bgcolor("black")
wn.setup(width=800, height=600)
wn.tracer(0)

# Paddle A
paddle_a = turtle.Turtle()
paddle_a.speed(0)
paddle_a.shape("square")
paddle_a.color("white")
paddle_a.shapesize(stretch_wid=5, stretch_len=1)
paddle_a.penup()
paddle_a.goto(-350, 0)

# Paddle B
paddle_b = turtle.Turtle()
paddle_b.speed(0)
paddle_b.shape("square")
paddle_b.color("white")
paddle_b.shapesize(stretch_wid=5, stretch_len=1)
paddle_b.penup()
paddle_b.goto(350, 0)

# Ball
ball = turtle.Turtle()
ball.speed(0)
ball.shape("square")
ball.color("white")
ball.penup()
ball.goto(0, 0)
ball.dx = 2
ball.dy = -2

# Function
def paddle_a_up():
    y = paddle_a.ycor()
    y += 20
    paddle_a.sety(y)

def paddle_a_down():
    y = paddle_a.ycor()
    y -= 20
    paddle_a.sety(y)

def paddle_b_up():
    y = paddle_b.ycor()
    y += 20
    paddle_b.sety(y)

def paddle_b_down():
    y = paddle_b.ycor()
    y -= 20
    paddle_b.sety(y)

# Keyboard binding
wn.listen()
wn.onkeypress(paddle_a_up, "w")
wn.onkeypress(paddle_a_down, "s")
wn.onkeypress(paddle_b_up, "Up")
wn.onkeypress(paddle_b_down, "Down")

# Main game loop
while True:
    wn.update() 

    # Move the ball
    ball.setx(ball.xcor() + ball.dx)
    ball.sety(ball.ycor() + ball.dy)

    # Border checking
    if ball.ycor() > 290:
        ball.sety(290)
        ball.dy *= -1

    if ball.ycor() < -290:
        ball.sety(-290)
        ball.dy *= -1

    if ball.xcor() > 390:
        ball.goto(0, 0)
        ball.dx *= -1

    if ball.xcor() < -390:
        ball.goto(0, 0)
        ball.dx *= -1

    # Paddle and ball collisions
    if (ball.xcor() > 340 and ball.xcor() < 350) and (ball.ycor() < paddle_b.ycor() + 40 and ball.ycor() > paddle_b.ycor() -40):
        ball.setx(340)
        ball.dx *= -1

    if (ball.xcor() < -340 and ball.xcor() > -350) and (ball.ycor() < paddle_a.ycor() + 40 and ball.ycor() > paddle_a.ycor() -40):
        ball.setx(-340)
        ball.dx *= -1

```

**UPDATE**

**SAMPLE**

**I meant while I was with the screen open, for example if it was a game I should count the time while I keep the program open.**

**I'd like a way to make it work within the script, but I'm also interested in command lines.**