turtle.setpos() and turtle.goto() functions in Python

turtle module in Python enables graphics using a virtual pen (turtle) and supports both object-oriented and procedural approaches. It relies on Tkinter for rendering, requiring a Python version with Tk support. The methods setpos(), setposition() and goto() move the turtle to a specified position and function identically, making them interchangeable.

Example: Moving the turtle to different positions

# import package
import turtle 

# forward turtle by 100
turtle.forward(100)

# stamp the turtle shape
turtle.stamp()

# set the position by using setpos()
turtle.up()
turtle.setpos(-50,50)
turtle.down()

# forward turtle by 100
turtle.forward(100)

# stamp the turtle shape
turtle.stamp()

# set the position by using goto()
turtle.up()
turtle.goto(-50,-50)
turtle.down()

# forward turtle by 100
turtle.forward(100)

Output

Explanation: Turtle moves forward 100 pixels, stamps its shape, then uses setpos(-50,50) to continue drawing. It moves to (-50,-50) with goto() and advances again. penup() lifts the pen to prevent drawing, while pendown() resumes it.

Syntax

import turtle

turtle.setpos(x, y=None)

# or

turtle.setposition(x, y=None)

# or

turtle.goto(x, y=None)

Parameters:

• x: The x-coordinate of the new position.
• y: The y-coordinate of the new position.
• If y is not provided, x must be a 2D vector (Vec2D object or tuple of (x, y)).

Functionality: These methods reposition the turtle to an absolute coordinate on the screen. The movement is direct and does not leave a trail unless penup() is used before calling these methods.

Examples

Example 1: Drawing a Circular Pattern with setpos()

import turtle

def draw(radius):
    # Draw a circle with the given radius
    turtle.circle(radius)
    
    # Move the turtle to a new position below the circle
    turtle.penup()
    turtle.setpos(0, -radius)
    turtle.pendown()

# Create a pattern with multiple concentric circles
for i in range(5):
    draw(20 + 20 * i)

turtle.done()

Output

Explanation: draw() function creates a circle of a specified radius. After drawing, the turtle moves to a new position below the circle. A loop generates five concentric circles, each with an increasing radius.

Example 2: Creating a Star with goto()

import turtle

turtle.penup()
turtle.goto(-100, 0)
turtle.pendown()

for i in range(5):
    turtle.forward(200)
    turtle.right(144)  # Turns the turtle to create a star

turtle.done()

Output

Explanation: Turtle moves to the starting position, then a loop draws a five-pointed star by moving forward and turning 144 degrees after each step.

Key Differences between goto() and setpos()

Although goto(x, y) and setpos(x, y) perform the same task, knowing their differences improves readability, ensures OOP consistency and enhances code maintainability based on coding style and context.