[Python-Dev] Pre-PEP: Allow Empty Subscript List Without Parentheses

Greg Ewing greg.ewing at canterbury.ac.nz
Sat Jun 10 01:55:06 CEST 2006

Alex Martelli wrote:

> Well, x=23 on one side, and  x[]=23 aka x[()]=23 on the other, have
> drastically different semantics. Indexing refers to the contents of
> the zero-dimensional container, rather than to a name to which the
> container happens to be bound (but isn't any more, once one assigns to
> that name rather than to an indexing thereof).

It's not clear to me that a 0-D array should be regarded
as a container holding a single item, rather than just an
item on its own.

Think about how you get from an N dimensional array to
an N-1 dimensional array: you index it, e.g.

   A2 = [[1, 2], [3, 4]] # a 2D array

   A1 = A2[1] # a 1D array

   A0 = A1[1] # a 0D array???

   print A0

What do you think this will print?


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