code: def date_range(start=None, stop=None, step=None):
  	
  	if step is None:
  		step = datetime.timedelta(days=1)
  	if start is None:
  		start = datetime.datetime.now()
  	while start < stop:
  		yield start
  		start += step
docs: Much like the built-in function range, but works with dates
  
  	>>> range_items = date_range(
  	...     datetime.datetime(2005,12,21),
  	...     datetime.datetime(2005,12,25),
  	... )
  	>>> my_range = tuple(range_items)
  	>>> datetime.datetime(2005,12,21) in my_range
  	True
  	>>> datetime.datetime(2005,12,22) in my_range
  	True
  	>>> datetime.datetime(2005,12,25) in my_range
  	False