python coding

  

lphabet = {
    ‘A’: ((0,0),(0.5,1),(0.75,0.5),(0.25,0.5),(0.75,0.5),(1,0)),
    ‘B’: ((0,0),(0,1),(0.625 ,1),(0.75,0.875),(0.75,0.625),(0.625,0.5),(0,0.5),(0.625,0.5),(0.75,0.375),(0.75,0.125),(0.625,0),(0,0)),
    ‘C’: ((0.75,0.125),(0.625,0),(0.125,0),(0,0.125),(0,0.875),(0.125,1),(0.625,1),(0.75,0.875)),
    ‘D’: ((0,0),(0,1),(0.625 ,1),(0.75,0.875),(0.75,0.125),(0.625,0),(0,0)),
    ‘E’: ((0.75,0),(0,0),(0,0.5),(0.75,0.5),(0,0.5),(0,1),(0.75,1)),
    ‘F’: ((0,0),(0,0.5),(0.75,0.5),(0,0.5),(0,1),(0.75,1)),
    ‘G’: ((0.75,0.5),(0.625,0.5),(0.75,0.5),(0.75,0.125),(0.625,0),(0.125,0),(0,0.125),(0,0.875),(0.125,1),(0.625,1),(0.75,0.875)),
    ‘H’: ((0,0),(0,1),(0,0.5),(0.75,0.5),(0.75,1),(0.75,0)),
    ‘I’: ((0,0),(0.25,0),(0.125,0),(0.125,1),(0,1),(0.25,1)),
    ‘J’: ((0,0.125),(0.125,0),(0.375,0),(0.5,0.125),(0.5,1)),
    ‘K’: ((0,0),(0,1),(0,0.5),(0.75,1),(0,0.5),(0.75,0)),
    ‘L’: ((0,0),(0,1),(0,0),(0.75,0)),
    ‘M’: ((0,0),(0,1),(0.5,0),(1,1),(1,0)),
    ‘N’: ((0,0),(0,1),(0.75,0),(0.75,1)),
    ‘O’: ((0.75,0.125),(0.625,0),(0.125,0),(0,0.125),(0,0.875),(0.125,1),(0.625,1),(0.75,0.875),(0.75,0.125)),
    ‘P’: ((0,0),(0,1),(0.625,1),(0.75,0.875),(0.75,0.625),(0.625,0.5),(0,0.5)),
    ‘Q’: ((0.75,0.125),(0.625,0),(0.125,0),(0,0.125),(0,0.875),(0.125,1),(0.625,1),(0.75,0.875),(0.75,0.125),(0.875,0)),
    ‘R’: ((0,0),(0,1),(0.625,1),(0.75,0.875),(0.75,0.625),(0.625,0.5),(0,0.5),(0.625,0.5),(0.875,0)),
    ‘S’: ((0,0.125),(0.125,0),(0.625,0),(0.75,0.125),(0.75,0.375),(0.675,0.5),(0.125,0.5),(0,0.625),(0,0.875),(0.125,1),(0.625,1),(0.75,0.875)),
    ‘T’: ((0,1),(0.5,1),(0.5,0),(0.5,1),(1,1)),
    ‘U’: ((0,1),(0,0.125),(0.125,0),(0.625,0),(0.75,0.125),(0.75,1)),
    ‘V’: ((0,1),(0.375,0),(0.75,1)),
    ‘W’: ((0,1),(0.25,0),(0.5,1),(0.75,0),(1,1)),
    ‘X’: ((0,0),(0.375,0.5),(0,1),(0.375,0.5),(0.75,1),(0.375,0.5),(0.75,0)),
    ‘Y’: ((0,1),(0.375,0.5),(0.375,0),(0.375,0.5),(0.75,1)),
    ‘Z’: ((0,1),(0.75,1),(0,0),(0.75,0)),
}

#Python Turtle – WordArt Challenge – www.101computing.net/python-turtle-wordart-challenge/
import turtle
import random
from alphabet import alphabet
from math import cos, sin, atan2, radians, degrees 

myPen = turtle.Turtle()
myPen.hideturtle()
myPen.speed(0)
window = turtle.Screen()
window.bgcolor(“#000000″)
myPen.pensize(2)

def displayMessage(message,fontSize,color,x,y,rotationAngle):
  myPen.color(color)
  message=message.upper()
  myPen.penup()
  myPen.goto(x,y)  
  for character in message:
    if character in alphabet:
      letter=alphabet[character]
      myPen.setheading(rotationAngle)
      myPen.penup()
    
      x=0
      y=0
      for dot in letter:
        angle = atan2((dot[1]-y),(dot[0]-x))
        angle= degrees(angle)    
  
        distance = ((dot[0]-x)**2 + (dot[1]-y)**2)**0.5
        myPen.setheading(rotationAngle)
  
        myPen.left(angle)
        myPen.forward(distance*fontSize)
        x = dot[0]
        y = dot[1]
        myPen.pendown()
  
      myPen.penup()
      angle = atan2((0-y),(0-x))
      angle = degrees(angle)    
  
      distance = ((0-x)**2 + (0-y)**2)**0.5
      myPen.setheading(rotationAngle)
  
      myPen.left(angle)
      myPen.forward(distance*fontSize)
  
    myPen.setheading(rotationAngle)
    myPen.penup()
    myPen.forward(fontSize)    
    
    myPen.forward(characterSpacing)
    

#Main Program Starts Here
fontSize = 30
fontColor=”#FF00FF”
characterSpacing = 5

message = “Hello World”
displayMessage(message,fontSize,fontColor,-170,-100,30)

i need explanation of each line how it works and what is the meaning of eachb syntex ?