Another situation in which I needed to disable such kind of warnings is while working with graphics modules. I often use variable names such as x, y, z for coordinates, or r,g,b for colors. Would longer names make the reader's life easier?
Best regards, Matteo On Wed, Oct 20, 2010 at 9:37 PM, Steven D'Aprano <st...@remove-this-cybersource.com.au> wrote: > On Wed, 20 Oct 2010 12:47:02 +0200, Jean-Michel Pichavant wrote: > >> except ValueError, e: >> >> Use meaningful names, this is so important. 'e' is not meaningful. >> 'exception' would be slighly better. > > While I agree with everything else you had to say, I have to take > exception to this comment [pun intended]. > > "e" as a short name for a generic exception instance is perfectly > reasonable, like: > > i, j, k for an index, or a loop variable > e.g. for i in range(100) > n for some other integer variable > s for a string > x for a float, or an arbitrary sequence object > e.g. [x.spam() for x in some_sequence] > > and similar. > > The last example is very instructive. What do you gain by racking your > brain for a "more meaningful" name instead of x? The obvious > alternatives, "obj" or "item", are equally generic as "x", they don't add > any further information. And how much information do you need? It's easy > to parody: > > [some_sequence_item.spam() for some_sequence_item in some_sequence] > > The very shortness of the name is valuable because it reduces the *human* > parsing time in reading, and there is no cost because the conventions are > so familiar. The convention of "for i in ..." says "this is a loop over > an integer" so strongly, that I would argue that "for index in ..." would > actually *delay* comprehension. > > Furthermore, the use of a single letter cues the reader that this > variable isn't notable -- there's nothing unusual or unconventional about > it, or it isn't the important part of the algorithm, or that its scope is > severely limited. For instance, consider the classic example of > exchanging two variables in Python: > > a, b = b, a > > versus: > > thing, other_thing = other_thing, thing > > The first example puts the emphasis on the *technique*, not the > variables. The second obscures it behind needlessly longer but still > generic names. > > You are absolutely right to insist on meaningful variable names. Where > you go wrong is to assume that single letter names can't be meaningful. > > > > -- > Steven > -- > http://mail.python.org/mailman/listinfo/python-list > -- Matteo Landi http://www.matteolandi.net/ -- http://mail.python.org/mailman/listinfo/python-list
