[Tutor] Making big 'uns into little 'uns

Ray Jones crawlzone at gmail.com
Thu Sep 6 16:59:52 CEST 2012

On 09/06/2012 07:48 AM, Dave Angel wrote:
>>> On 09/06/2012 09:56 AM, Ray Jones wrote:
>>>> I have a multiple 'if' expression that I need to drastically reduce in
>>>> size, both for readability and to keep errors from creeping in.
>>>> For example, I would like to have the variable 'test' point to the a
>>>> location 'grid[rcount-1][ccount-1]' so that everywhere I would use
>>>> 'grid.....', I could replace it with 'test' How would I accomplish that?
>>>> Thanks.
> I don't know your use-case.  For that matter, I don't even know what
> semantics you mean by the grid[xx][yy] expression.  For example, are
> grid, rcount, and ccount globals?  Or are you constraining 'test' to
> only be used in the context where they are all visible?   Or are you
> defining this location as the offset within grid where rcount and ccount
> happen to point to right now?  I can see maybe a dozen "reasonable"
> meanings, each requiring a different sets of constructs in the language
> or its preprocessor.
> One thing you can do in Python, but not in any other language I've used,
> is to define a class instance property.  For example, if you were
> willing to use q.test instead of test, you could do something like:
> class Q(object):
>     @property
>     def test(self):
>         return grid[rcount-1][ccount-1]
> That would give you readonly access to an object defined by 3 variables
> that have to be visible to the Q code.  And you could make the
> expression more complex if grid is defined elsewhere, for example.
> Now once you do  q = Q(), you can use
>     q.test  instead of the larger expression.
> Lots of other possibilities in Python.  But not with exactly your
> original syntax.  Using this one as is would be ugly code, as is your
> original example.  So presumably you have an actual use-case where this
> makes sense, other than saving typing.
Basically it's as simple as ensuring that an array consists of integers,
and that those integers fall within a certain range. Rather than using
multiple 'if' statements, I was (am, at this point) using multiple tests
within a single 'if' statement. Nothing earth-shatteringly difficult,
but I was simply looking for a way to shorten the overall test
expression with a recursive(? is that the term) variable. No problem though.



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