Python Forum

import tkinter
from math import sin, cos, radians

# DrawWindow - a class for creating a window with a canvas
class DrawingWindow(tkinter.Frame):
    def __init__(self):
        tkinter.Frame.__init__(self,None)
        self.canvas = tkinter.Canvas(self,width=500,height=500,bg='white')
        self.canvas.pack(expand=1,anchor=tkinter.CENTER)
        self.pack()

def draw_spiral(x,y,angle,dangle,length,dlength,steps,canvas):
    # x,y - starting position of the current line segment
    # angle - angle of current line segment (0 is straight up)
    # dangle - change in angle for each recursion
    # length - length of current line segment
    # dlength -  value to divide length with each step
    # steps - number of recursion steps left
    # canvas - canvas window to draw on
    if steps == 0:
        # Bas case -stop here
        pass
    else:
        # Recursive case
        # Draw one line segment from (x,y) with the given angle and length
        # Calulate end points of this line
        x2 = x+sin(radians(angle))*length
        y2 = y-cos(radians(angle))*length
        # Draw the line on the canvas
        canvas.create_line(x,y,x2,y2)
        # Recursive call, with end points the drawn lines as new start points,
        # with an increase in the angle (turn clockwise)
        # and a smaller length, and with step counted down with 1
        draw_spiral(x2,y2,angle+dangle, dangle,length/dlength,dlength,steps-1,canvas)

# Create window for drawing on
w = DrawingWindow()
# Draw the spiral on the canvas of that window
# Try to change the parameters and see what happens
draw_spiral(250,250,90,60,100,1.1,35,w.canvas)
# Start the window, so it is displayed
w.mainloop()

from turtle import Turtle, mainloop
def tree(plist, l, a, f):
    """ plist is list of pens
    l is length of branch
    a is half of the angle between 2 branches
    f is factor by which branch is shortened
    from level to level."""
    if l > 5: 
        lst = []
        for p in plist:
            p.forward(l)
            q = p.clone()
            p.left(a)
            q.right(a)
            lst.append(p)
            lst.append(q)
        tree(lst, l*f, a, f)

def main():
    p = Turtle()
    p.color("green")
    p.pensize(5)
    p.speed(100)
    p.left(90)
    p.penup()
    p.goto(0,-200)
    p.pendown()
t = tree([p], 200, 65, 0.6)
main()