John Salerno wrote:
Hey all. I've decided I let my Python skills (minor though they were)
slip away so I started reading the new edition of Learning Python to
brush up. I just read about lists again and I'm wondering if someone
could explain what's going on under the hood that makes index and slice
assignments behave differently when assigning an empty list.
For example:
>>> L = [1, 2, 3, 4, 5]
>>> L[0:2] = []
>>> L
[3, 4, 5]
>>> L = [1, 2, 3, 4, 5]
>>> L[0] = []
>>> L
[[], 2, 3, 4, 5]
So the question is, when you assign an empty list to an index, why does
it insert an empty list, but when you assign an empty list to a slice,
it simply deletes the slice?
Assignment to a list *element* rebinds the single element to the
assigned value. Assignment to a list *slice* has to be of a list, and it
replaces the elements in the slice by assigned elements.
regards
Steve
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Holden Web LLC http://www.holdenweb.com/
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