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why won't slicing lists raise IndexError?

Python python at bladeshadow.org
Wed Dec 6 16:11:01 EST 2017 
On Tue, Dec 05, 2017 at 06:23:04PM -0800, Rick Johnson wrote:
> [bunch of old, irrelevant context snipped]
> > item = seq[n:n+1]
> > if item:
> >      process(item)
> > else:
> >      do_without_item()
> 
> When Python follows a logic clause like a train skating
> along a set of railroad tracks, and finds itself in a *GHOST
> TOWN*, that's not an action -- "Steve-o" -- it's a non-
> action.

Geez, seriously?  The snippet is purely academic, obviously not a
complete or useful program, intended to illustrate that python can
take two different branches depending on whether or not the slicing
operation yeilded a non-empty container, using uncomplicated syntax.
It effectively serves that purpose.

Moreover, in order for the example to make sense, we must assume the
existence of unspecified code:  The variables need to have been
initialized previously, or else the snippet is non-functional.  The if
conditional would never be reached.  We can as easily assume that the
hypothetical example continues with other, unspecified code, and that
the equally unspecified do_without_item() actually does something,
which renders your argument completely invalid and pointless.

The whole thing is entirely academic; continuing to argue this is an
utter waste of time and bandwidth.
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