text: """tools for measuring time
  """
  
  
  def timer(f):
      '''
      decorator to print execution time of a function
      :param f:
      '''
  
      def timedFunction(*args, **kwargs):
          t0 = time()
          out = f(*args, **kwargs)
          t1 = time()
          print("timer :", f.__name__, t1 - t0)
          return out
  
      return timedFunction
  