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

Sat Jun 10 05:25:31 CEST 2006

On Jun 9, 2006, at 4:55 PM, Greg Ewing wrote:
 ...
> 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?

Don't confuse arrays with lists...:
 >>> A2 = Numeric.array([[1, 2], [3, 4]], Numeric.Float32)
 >>> A1 = A2[1]
 >>> A0 = A1[1]
 >>> type(A0)
<type 'array'>
 >>>
It doesn't work the same if you specify Numeric.Float64 instead -- an 
ancient wart of Numeric, of course. Still, Numeric and its 
descendants are "the" way in Python to get multi-dimensional arrays, 
since the stdlib's array module only supports one-dimensional ones, 
and lists are not arrays.
Alex