CS 111 - 9/22/16

For the lab quiz on Monday, expect questions similar to
  last Monday's quiz

    x = 2
    z = 0
    for w in range (5)
        z = z + x


    x = 1
    z = 0
    for w in range (5)
        z = z + x
        x = x + 1

In the code above, w is often called the "loop varaible"

The range(N) function in python produces a list of values
   from 0 to N-1

  z = 0
  for w in range (5):
    print w
    z = z + w
    
  print "After the loop, the value of z is"  
  print z


Chapter 4 - Pictures

  How pictures are encoded?


    - Picture
       - pixels (PIcture ELements), a grid 
           - 3 colors (red, green, blue)
                - a number in range from 0 to 255