why no block comments in Python?

[John Salerno]

I'm still tyring to figure out what "Pythonic" means, and I have a
feeling the answer to my question may fall into that category. Are block
comments somehow unpythonic?

[Benji York]

Terry Hancock wrote:

I'm thinking this might be a use-case for the new support for
doctests in a separate file.

Having doctests in their own file is (IMHO) a majorly under appreciated
feature of doctest. The ability to do either nice user (as in
developer) docs with known good examples or well documented
not-meant-for-documentation unit/functional/integration tests is terrific.
--
Benji York

[msoulier]

> (and if you don't, you can quickly comment out regions by putting them

inside a triple-quoted string.)

Although that will use up memory, as opposed to a comment.

Still, it's simple enough in an editor like Vim or Emacs to highlight a
region, and define a macro to add/remove #s. Any Python IDE should
certainly have this capability.

Mike

[Roy Smith]

msoulier <ms******@gmail .com> wrote:

(and if you don't, you can quickly comment out regions by putting them
inside a triple-quoted string.)

Although that will use up memory, as opposed to a comment.

I can't imagine a realistic scenario where the amount of memory wasted
by triple-quoting out code could possibly be significant.

I'll also repeat what I said before -- good software engineering
practice demands that you remove dead code completely. Commenting
something out for a quick test during development is OK, but once it
reaches the production stage, get rid of it. It'll still live in your
revision control system.

[Peter Otten]

msoulier wrote:

(and if you don't, you can quickly comment out regions by putting them
inside a triple-quoted string.)

Although that will use up memory, as opposed to a comment.

Doesn't seem so:

def f(): .... "docstring"
.... "another string"
.... a = 42
.... "yet another string"
.... f.func_code.co_ consts ('docstring', 42, None)

Peter

[Terry Hancock]

On 9 Mar 2006 07:21:00 -0800
"msoulier" <ms******@gmail .com> wrote:

(and if you don't, you can quickly comment out regions
by putting them inside a triple-quoted string.)

Although that will use up memory, as opposed to a comment.

Not really. Unless it is the first string in the block
(class, function, module), it won't be assigned to anything,
and will be immediately garbage-collected.

It may consume space in the pyc file, I'm not sure.

Of course, I don't think anyone would advocate leaving
such things in production code where the memory use
would be an issue anyway. The whole point of
block-commenting code out is to temporarily "delete" it
without having to use your version control system to get
it back. You only do that when you have strong feeling
you're going to need to put it back in.

--
Terry Hancock (ha*****@Anansi Spaceworks.com)
Anansi Spaceworks http://www.AnansiSpaceworks.com

[Steven D'Aprano]

On Thu, 09 Mar 2006 18:02:27 -0600, Terry Hancock wrote:

On 9 Mar 2006 07:21:00 -0800
"msoulier" <ms******@gmail .com> wrote:

> (and if you don't, you can quickly comment out regions
> by putting them inside a triple-quoted string.)

Although that will use up memory, as opposed to a comment.

Not really. Unless it is the first string in the block
(class, function, module), it won't be assigned to anything,
and will be immediately garbage-collected.

It may consume space in the pyc file, I'm not sure.

I don't believe this is true. Unassigned strings other than the doc string
are not compiled into the code:

def f(x): .... "this is a doc string"
.... "but this isn't"
.... return "hello world"
.... dis.dis(f) 4 0 LOAD_CONST 1 ('hello world')
3 RETURN_VALUE
4 LOAD_CONST 2 (None)
7 RETURN_VALUE
Strangely enough, this is a local optimization that appears to have been
done only for strings:
def g(): .... 45
.... return 55
.... dis.dis(g)

2 0 LOAD_CONST 1 (45)
3 POP_TOP

3 4 LOAD_CONST 2 (55)
7 RETURN_VALUE
8 LOAD_CONST 0 (None)
11 RETURN_VALUE

So you should feel free to use strings (triple-quoted or otherwise) as
documentation in your functions.

--
Steven.

[Terry Hancock]

On Sat, 11 Mar 2006 10:23:56 +1100
"Steven D'Aprano" <st***@REMOVETH IScyber.com.au> wrote:

On Thu, 09 Mar 2006 18:02:27 -0600, Terry Hancock wrote:

On 9 Mar 2006 07:21:00 -0800
"msoulier" <ms******@gmail .com> wrote:

> (and if you don't, you can quickly comment out

regions > > by putting them inside a triple-quoted
string.) >

Although that will use up memory, as opposed to a

comment.

Not really. Unless it is the first string in the block
(class, function, module), it won't be assigned to
anything, and will be immediately garbage-collected.

It may consume space in the pyc file, I'm not sure.

I don't believe this is true. Unassigned strings other
than the doc string are not compiled into the code:

[bytecode analysis snipped]

Cool. I thought that was probably true, but didn't want
to guess.

Cheers,
Terry
--
Terry Hancock (ha*****@Anansi Spaceworks.com)
Anansi Spaceworks http://www.AnansiSpaceworks.com

[Jonathan Gardner]

Warby wrote:

...and I forgot to mention that the output of grep and diff is far more
understandable in the absence of block comments!

Which is why people do this /anyway/. (Kind of makes block comments
pointless, doesn't it?

/* This is a
* really
* really
* long
* block comment */

[Roy Smith]

In article <11************ *********@v46g2 000cwv.googlegr oups.com>,
"Jonathan Gardner" <jg******@jonat hangardner.net> wrote:

Warby wrote:

...and I forgot to mention that the output of grep and diff is far more
understandable in the absence of block comments!

Which is why people do this /anyway/. (Kind of makes block comments
pointless, doesn't it?

/* This is a
* really
* really
* long
* block comment */

Habit left over from the C days. It was the only way of making a block
comment stand out visually. C++ has // comments, just like Python has #,
but old habits die hard.