old_contents: """Fibonacci series:
  
  0, 1, 1, 2, 3, 5, 8,... 
  
  - Fib(0) = 0
  - Fib(1) = 1
  - Fib(n) = Fib(n - 1) + Fib(n - 2)
  """
  
  from __future__ import print_function
  import time
  
  
  def fibonacci(n):
      """Get nth number of Fibonacci series by recursion."""
      if n == 0:
          return 0
      elif n == 1 or n == 2:
          return 1
      else:
          return fibonacci(n - 1) + fibonacci(n - 2)
  
  
  def main():
      n = 13
      print('{}th number of Fibonacci series: {}'
            .format(n, fibonacci(n)))
  
  
  if __name__ == '__main__':
      main()
  
new_contents: """Fibonacci series:
  
  0, 1, 1, 2, 3, 5, 8,... 
  
  - Fib(0) = 0
  - Fib(1) = 1
  - Fib(n) = Fib(n - 1) + Fib(n - 2)
  """
  
  from __future__ import print_function
  
  
  def fibonacci(n):
      """Get nth number of Fibonacci series by recursion."""
      if n == 0:
          return 0
      elif n == 1 or n == 2:
          return 1
      else:
          return fibonacci(n - 1) + fibonacci(n - 2)
  
  
  def main():
      import time
      n = 13
      print('{}th number of Fibonacci series: {}'
            .format(n, fibonacci(n)))
  
  
  if __name__ == '__main__':
      main()
  
subject: Move module time to main()