Array slicing involves taking a subset from an array and allocating a new array with those elements.
In Python you can create a new list of the elements in my_list, from start_index to end_index (exclusive), like this:
You can also get everything after start_index by just omitting end_index:
Careful: there's a hidden time and space cost here! It's tempting to think of slicing as just "getting elements," but in reality you are:
- allocating a new list
- copying the elements from the original list to the new list
This takes time and space, where n is the number of elements in the resulting list.
That's a bit easier to see when you save the result of the slice to a variable:
But a bit harder to see when you don't save the result of the slice to a variable:
So keep an eye out. Slice wisely.
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