#import Python turtle module
#More info see https://docs.python.org/2/library/turtle.html
import turtle
##Make turtle t recursively draw a tree
def drawTree(branchLen,t):
if branchLen <= 10: #base case
t.forward(10)
t.backward(10)
else:
#draw the trunk
t.forward(branchLen)
#draw branches
t.right(20)
drawTree(branchLen-15,t)
t.left(40)
drawTree(branchLen-15,t)
t.right(20)
#go back to the starting point
t.backward(branchLen)
##Initialize the turtle
t = turtle.Turtle()
t.speed(6) #Set the turtle speed. 1 is slow and 10 is fast.
t.color("green")#Set the turtle color.
t.pensize(2) #Set the pen size
myWin = turtle.Screen()
##Initialize the pen position
t.left(90) #Turn turtle left by 90 degrees.
t.up() #Pull the pen up - no drawing when moving.
t.backward(100) #move the pen backward by 100
t.down() #Pull the pen down - drawing when moving.
#draw the tree
drawTree(70,t)
##exit the drawing screen
myWin.exitonclick()
Program Revised from http://interactivepython.org/runestone/static/pythonds/Recursion/pythondsintro-VisualizingRecursion.html
