[Python-Dev] Pre-PEP: Allow Empty Subscript List Without Parentheses (original) (raw)

Noam Raphael noamraph at gmail.com
Sat Jun 17 23:44:52 CEST 2006

2006/6/17, "Martin v. Löwis" <martin at v.loewis.de>:

Noam Raphael wrote: > I meant the extra code for writing a special class to handle scalars, > if I decide that the "x[()]" syntax is too ugly or too hard to type, > so I write a special class which will allow the syntax "x.value".

What I cannot understand is why you use a zero-dimensional array to represent a scalar. Scalars are directly supported in Python: x = 5

I need a zero-dimensional array as a single cell - an object that holds a value that can change over time. It works just like a cell in a spreadsheet: For example, say that if you change the value of cell A1 to 0.18, cell A2 changes to 5. When using the library I design, you would write "sheet1[0, 0] = 0.18", and, magically, "sheet1[0, 1]" will become 5. But in my library, everything is meaningful and doesn't have to be two-dimensional. So, if in the spreadsheet example, A1 meant the income tax rate, you would write "income_tax[] = 0.18", and, magically, "profit['Jerusalem', 2005]" will become 5.

I hope I managed to explain myself - my use case and why the simplest way to treat scalars like income_tax is as zero-dimensional arrays.

Also, in an assignment, what are you putting on the right-hand side? A read access from another zero-dimensional array? I hope my example explained that, but you can put there any object - for example, you can write "income_tax[] = 0.18"

(If I didn't yet manage to explain myself, please say so - it seems that it's not a very simple example and I'm not a very good explainer, at least in English.)

Noam

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