[Python-Dev] An ability to specify start and length of slices

[Jeff Epler]

Some questions:

At the top, you mention the syntax
    object[start:>length:jump]
  but you never explain what that does.  Is it equivalent to
    object[start:start+length*jump:jump] # give length items
  or
    object[start:start+length:jump] # give length/jump items
  ?

What about negative strides?

Is there a way to ask for the length items just before stop, for
instance
    object[>length:start:jump]
?

About Tim's suggestion:

Pretending for a moment that it could fly, can we make sure this works
with dicts, and also create +, for tuples and lists?

I'd like
    { 1 +: 3 }
to create the dict {1:4}, and for
    1, 3 +, 5
to create the tuple (1, 3, 8)

One last comment -- While you'll have a hard sell with this new syntax
idea, having an implementation for it makes you stand above all the
other people peddling their bad syntax change on the mailing lists.

Jeff
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