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Python Object-Oriented Python Advanced Objects Subclassing Built-ins

Posted by Kia Matthews
Kia Matthews
3,402 Points

Why does self.[::-1] return the reverse of the string when used in defining the class?

I thought [::] was used for lists only?

1 Answer

Jon Mirow
Jon Mirow
9,864 Points

Hi there! Slicing in python is a tool used for ordered collections. So strings, lists, tuples can all be sliced because they have an order. unordered collections like sets and dictionaries can't be sliced by index. What's unique about lists in python's ordered collections is that they can be changed without creating an new instance of the collection - they are said to be mutable. Strings and Tuples are immutable - you can slice them to get values from them, but if you wanted to change them in anyway you have to make a new string/tuple.

Hope it helps

Kia Matthews
Kia Matthews
3,402 Points

Ah yes. I was thinking it was for mutable objects only. Thanks for clearing that up!