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Name: Ang Li, Jash Rathod

Lab: Draw a Fibonacci Spiral

Date: Feb 22, 2018

Class: CS 111

This programe helps us draw the fibonacci spiral based on the input of number of layers from the user.

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import turtle

tortoise=turtle.Turtle()

def fib(n):

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This function is to calculate the Fibonacci sequence.

Parameters:

n: is the numbers that will be in the Fibonacci sequence

Return values:

The return values will be b who is the number is the Fibonacci sequence

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a=0

b=1

for i in range(2,n+1):

a = a + b

a,b = b,a

return b #Returns the fibonacci vaue

def ss(n): #Drawing the squares and spirals

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This function is to draw a square whose sides is the number inside Fibonacci sequence and

the arcs which will form the spiral.

Parameters:

n: is the number that will be the side of the squares and the radius of the arc in the

fibonacci sequence.

Tortoise: is the turtle who will draw the square.

Return Value:

None

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for segment in range(4): #Loop index is defined as 4 for loop function for square

tortoise.forward(fib(n)*5)

tortoise.left(90)

tortoise.pencolor(‘blue’)

tortoise.pensize(3)

tortoise.circle(fib(n)*5,90)

tortoise.pencolor(‘red’)

tortoise.pensize(1)

def main():

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This is the main function to draw the Fibonacci spiral as it calls the other fucntions that calculates the fibonacci sequence and drawas the squares and arcs based on the calculations

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tortoise.hideturtle()

tortoise.speed(10)

n=int(input('How many layers: ')) #Asks user to input the number of layers

for i in range(n+1): #Loop index is defined as n+1 for loop function

ss(i)

screen=tortoise.getscreen()

screen.exitonclick()

main()

ImportErrorTraceback (most recent call last)

in ()

7 This programe helps us draw the fibonacci spiral based on the input of number of layers from the user.

8 “”"

----> 9 import turtle

10 tortoise=turtle.Turtle()

11 def fib(n):

/usr/lib/python2.7/lib-tk/turtle.py in ()

105 #print _ver

106

–> 107 import Tkinter as TK

108 import types

109 import math

/usr/lib/python2.7/lib-tk/Tkinter.py in ()

40 import _tkinter

41 except ImportError, msg:

—> 42 raise ImportError, str(msg) + ‘, please install the python-tk package’

43 tkinter = _tkinter # b/w compat for export

44 TclError = _tkinter.TclError

ImportError: No module named _tkinter, please install the python-tk package