#! /usr/bin/python

a,b = 0,1

while a < 1000:
  print a
  a,b = b,a+b

print b



def fib(n):
  a,b = 0,1
  while a < n:
    print a
    a,b = b,a+b
  return b        # if omitted, return the value 'None'


print fib(100)
print b


frog1 = (50,100,"up")
# pattern matching for de-structing tuples:
(x,y,vel) = frog1



WORLD_WIDTH = 500
import random    # can now use random.randint(), etc.

class Princess:
  WAIT_TIME = 10

  def update(self):
    self.timeLeft = self.timeLeft - 1
    if self.timeLeft == 0:
      self.timeLeft = Princess.WAIT_TIME;
      self.x = random.randrange(WORLD_WIDTH)

  # A constructor:
  #
  def __init__(self, _x):
    self.x = _x
    self.timeLeft = Princess.WAIT_TIME

  # Override the 'str' function:
  #
  def __str__(self):
    return 'Princess:' + str(self.__dict__)

p = Princess(50)
print str(p)    # could also just say `print p`
p.update()
print str(p)


i = 0
while i < Princess.WAIT_TIME + 2:
  p.update()
  i = i + 1
print Princess.WAIT_TIME+2, "units later", p