commenting out blocks of code

[Steven D'Aprano]

On Fri, 17 Feb 2006 19:12:01 -0500, Peter Hansen wrote:

> john peter wrote:
>> is there a similar mechanism in python, other than prefixing
>> the '#' character to the start of each statement i do  not
>> want to execute (which gets old very quickly if one needs to
>> comment and uncomment several statements a couple of
>> times while "playing around with code" say during initial design)?
> 
> In addition to the approach Paul has suggested, you should also consider 
> using a better editor, as most decent editors should have some kind of 
> "block comment/uncomment" feature that prevents that operation from 
> getting old very quickly...
> 
> Scite, for example, lets me selected a block and hit Ctrl-Q to either 
> comment or uncomment the block.

I see the developers of Scite are either newbies to GUI programming, or
they operate in a world of their own. Ctrl-Q is reserved for Quit (or
Exit) in every GUI API I know of.


> (It does this by prefixing each line 
> with #~ instead of just #, which allows it to detect when a line is 
> already so commented and reverse the operation.)  

It is *easy* to detect when a line is already commented. It starts with a
#. The ~ is superfluous.

Commenting and uncommenting should be two different commands: the whole
point of nested comments is that it allows you to comment a block of text
which may already contain comments. Having one command do both commenting
and uncommenting according to the presence or absence of semantic clues in
the text is a recipe for failure ("No you stupid computer, I want to
COMMENT that block, not uncomment it!!!").

Imagine if your text editor used cntl-C for both copy and paste, somehow
guessing whether you wanted to copy selected text or paste over it
according to some subtle clue in the text itself. Wouldn't that be fun?



-- 
Steven.