text: from __future__ import absolute_import
  
  import time
  import humanfriendly as hf
  
  class Timer(object):
      """Prints the elapsed time after the execution of a block of code
         finishes.
      """
      def __init__(self, verbose=True):
          self._verbose = verbose
          self._tstart = None
          self.elapsed = None
  
      def __enter__(self):
          self._tstart = time.time()
          return self
  
      def __exit__(self, type_, value_, traceback_):
          self.elapsed = time.time() - self._tstart
          if self._verbose:
              print('Elapsed time: %s.' % hf.format_timespan(self.elapsed))
  