* Ben Finney (Sun, 30 Dec 2007 15:36:12 +1100) > Steven D'Aprano <[EMAIL PROTECTED]> writes: > > On Sat, 29 Dec 2007 15:29:25 +0000, Thorsten Kampe wrote: > > > I'd personally go for spaces because: > > > > > > 1. I don't like things I cannot see (control characters) > > > > You can see spaces but not tabs? Your editor is pretty weird. In all > > the editors I've every used, both spaces and tabs show up as empty > > white space. (Or coloured space if I set the editor to use a > > coloured background.) > > Though Thorsten could have been clearer, "thing that is not a space > character but shows up as white space" is a near-enough approximation > of "thing I cannot see". > > > > 2. I never had problems with spaces but plenty with tabs > > > > Periodically, I ask on this list what problems people have with > > tabs. (I'm fully aware that mixing tabs and spaces is a Bad Thing.) > > I've had little luck getting any answer except "Tabs are bad, > > m'kay?". > > Posit: White space is most often achieved by the user inserting a > sequence of space characters (U+0020). > > Posit: Tab characters (U+0009) are, in a majority of environments, > rendered visually indistinguishable from a sequence of space > characters. > > Corollary: most readers will, when seeing a stretch of white space on > a line, default to assuming that it represents a sequence of space > (U+0020) characters. > > Corollary: So when a file containing either spaces or tabs is edited > in such an environment, the common way chosen by the user to get to > the same indentation level as existing lines is to prepend space > characters (using the spacebar or the Tab key or whatever facility the > editor provides) until the indentation lines up visually -- > remembering the caveat that tabs and space-sequences are visually > indistinguishable in many environments. > > Argument: The user will get an unexpected result when they do the > obvious thing (prepend space characters) in a tabs-only file. With > existing spaces-only files, the obvious way to get matching > indentation gives the expected result. > > Conclusion: Thus, using tabs-only is inferior to using spaces-only for > indentation, because it violates the Principle of Least Astonishment > <URL:http://en.wikipedia.org/wiki/Principle_of_least_astonishment>.
Man, how did you know what I wanted to say (but failed to to express) :-) ? Anyway: the consequence of your well done argumentation is that someone editing Python code has to use a specialised editor to prevent screwing up tab indented code - and that's bad. Thorsten -- http://mail.python.org/mailman/listinfo/python-list