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Noah Fields
13,985 PointsWhy use [:: -1] instead of reversed function?
In the video 'Slicing With A Step' Kenneth ends by showing how you can reverse a list with the command [: : -1], which slices an entire list and runs through it from end to beginning at a step of -1. However, this can also be done using the keyword "reversed". So,
new_thing = arg [::-1]
becomes
new_thing = list(reversed(arg))
The latter can only be used if you're slicing the entire list, with no steps involved, as it simply takes the whole list and reverses it. Other than that, however, what are the advantages to the reversed keyword as opposed to a full negative slice of the list?
1 Answer
Steven Parker
243,656 PointsThe slice method is more compact.
Plus it saves a step since it returns a list, but the reversed function output must be converted into a list.
Kent Ã…svang
18,823 PointsKent Ã…svang
18,823 PointsThere is no particular note-worthy benefit of using one or the other. Of course slicing gives you a little more flexibility, but for this exact exercise it is just a matter or taste. Perhaps the .reversed-method is a little more explanatory in terms of readable code.