What does the slice() function do in Python?

Question

First of all, I\'d like to clarify the question: it\'s about the slice() function, not slices of lists or strings like a[5:4:3].

The docs menti

Answer 1

(Using function semantics) Calling the slice class instantiates a slice object (start,stop,step), which you can use as a slice specifier later in your program:

>>> myname='Rufus'
>>> myname[::-1] # reversing idiom
'sufuR'

>>> reversing_slice=slice(None,None,-1) # reversing idiom as slice object
>>> myname[reversing_slice]
'sufuR'

>>> odds=slice(0,None,2) # another example
>>> myname[odds]
'Rfs'

If you had a slice you often used, this is preferable to using constants in multiple program areas, and save the pain of keeping 2 or 3 references that had to be typed in each time.

Of course, it does make it look like an index, but after using Python a while, you learn that everything is not what it looks like at first glance, so I recommend naming your variables better (as I did with reversing_slice, versus odds which isn't so clear.