Introducing Turtle Graphics

• Open REPL.it, start a new REPL project of Turtle-Graphics
• On first two lines, enter:
  import turtle
  t = turtle.Turtle()
• Try the following commands:
  • t.forward(50)
  • t.backward(50)
  • t.left(90)
  • t.right(90)

Drawing basic shapes with for loop

New commands

• setcolor( (r, g, b) )
  • Note there's one more bracket around the rgb value
  • The range of RGB is 0-255, e.g.
  • setcolor( (255, 255, 255) )  - white
  • setcolor( (255, 0, 0) ) - Red
• setpos( x, y )
  • Move the turtle to the absolute position
• penup() , pendown()

Let's try to draw this

Copy this pattern in the notebook, write down the step by step sequence for it:

t.fd(   )
t.lt(   )

t.fd(   )
t.lt(   )

t.fd(   )
t.lt(   )

t.fd(   )
t.lt(   )

What is the pattern?

t.fd(    )
t.lt(90)

 

fd is just repeating with different number!

What is the formula for the pattern? 

What is the range for the pattern?

 

while width in range([start], [stop-1]):
  t.fd( [formula with width] )
  t.lt(90)

1. Complete the Square spiral,
2. Try with a triangle pattern,
3. You can also ask user input the number of repeat and number of sides you want for a spiral generator

Extra challenge - combining with color function