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.
Thanks. Ray _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
