visual indentation

**achrist@easystreet.com** · Jul 18 '05, 01:54 AM

Re: visual indentation

Hilbert wrote:[color=blue]
>
> Hello,
>
> I'm using python to output RIB streams for Renderman.
> The RIB stream is a bunch of statements which describes
> a 3d image. The Rib standard allows for blocks which we
> usually indent for better visualization for example:
>
> WorldBegin
> Color [1 1 1]
> Surface "constant"
> Sphere(1.0, -1.0, 1.0, 360)
> WorldEnd
>
> I'm using CGKit in python which has a Renderman binding,
> so to output the same RIB I'd write:
>
> RiWorldBegin()
> RiColor(1.0,1.0 ,1.0)
> RiSurface('cons tant')
> RiSphere(1.0,-1.0,1.0,360)
> RiWorldEnd()
>
> But I get an error, because python interprets my indentation
> as a block in the python code. So the only way to write this
> is without the indentation:
>
> RiWorldBegin()
> RiColor(1.0,1.0 ,1.0)
> RiSurface('cons tant')
> RiSphere(1.0,-1.0,1.0,360)
> RiWorldEnd()
>
> But this is a lot harder to read.
>
> Is there any way to use such "visual" indentation in python?
>[/color]

If the code is purely sequential, how about something like this:

import string
def RunTheseStateme nts(s):
stmts = map(string.stri p, s.split("\n"))
for stmt in stmts:
eval(stmt)

RunTheseStateme nts("""

RiWorldBegin()
RiColor(1.0,1.0 ,1.0)
RiSurface('cons tant')
RiSphere(1.0,-1.0,1.0,360)
RiWorldEnd()

""")

Al

**Peter Otten** · Jul 18 '05, 01:54 AM

Re: visual indentation

Hilbert wrote:
[color=blue]
> Is there any way to use such "visual" indentation in python?[/color]

Whitespace *is* significant in Python, and you should not try to circumvent
this using dirty tricks. Why not structuring your world definitions in the
standard way, putting the things that belong together in separate functions
or classes?

#disclaimer: no knowledge of CGKit involved in the following code
WHITE = (1.0,1.0,1.0)

def whitesurface():
RiColor(*WHITE)
RiSurface('cons tant')

def firstworld():
whitesurface()
RiSphere(1.0,-1.0,1.0,360)

def secondworld():
whitesurface()
RiSphere(1.0,-1.0,1.0,360)

for world in [firstworld, secondworld]:
RiWorldBegin()
world()
RiWorldEnd()

I think the above is pretty readable, and you can always factor out
repeating chunks of code

Peter

**Greg Krohn** · Jul 18 '05, 01:54 AM

Re: visual indentation

"Hilbert" <Hilbert@panka. com> wrote in message
news:slrnbkcja7 .s51.Hilbert@se rver.panka.com. ..[color=blue]
> Hello,
>
> I'm using python to output RIB streams for Renderman.
> The RIB stream is a bunch of statements which describes
> a 3d image. The Rib standard allows for blocks which we
> usually indent for better visualization for example:
>
> WorldBegin
> Color [1 1 1]
> Surface "constant"
> Sphere(1.0, -1.0, 1.0, 360)
> WorldEnd
>
> I'm using CGKit in python which has a Renderman binding,
> so to output the same RIB I'd write:
>
> RiWorldBegin()
> RiColor(1.0,1.0 ,1.0)
> RiSurface('cons tant')
> RiSphere(1.0,-1.0,1.0,360)
> RiWorldEnd()
>
> But I get an error, because python interprets my indentation
> as a block in the python code. So the only way to write this
> is without the indentation:
>
> RiWorldBegin()
> RiColor(1.0,1.0 ,1.0)
> RiSurface('cons tant')
> RiSphere(1.0,-1.0,1.0,360)
> RiWorldEnd()
>
> But this is a lot harder to read.
>
> Is there any way to use such "visual" indentation in python?
>
> Thanks,
> Hilbert
>
> hilbert@panka.c om
>
>[/color]

What about an if statement:

RiWorldBegin()
if True:
RiColor(1.0,1.0 ,1.0)
RiSurface('cons tant')
RiSphere(1.0,-1.0,1.0,360)
RiWorldEnd()

I realize it's ugly, but it's easy.

**Gary Herron** · Jul 18 '05, 01:54 AM

Re: visual indentation

On Friday 22 August 2003 11:28 am, achrist@easystr eet.com wrote:[color=blue]
> Hilbert wrote:[color=green]
> > Hello,
> >
> > I'm using python to output RIB streams for Renderman.
> > The RIB stream is a bunch of statements which describes
> > a 3d image. The Rib standard allows for blocks which we
> > usually indent for better visualization for example:
> >
> > WorldBegin
> > Color [1 1 1]
> > Surface "constant"
> > Sphere(1.0, -1.0, 1.0, 360)
> > WorldEnd
> >
> > I'm using CGKit in python which has a Renderman binding,
> > so to output the same RIB I'd write:
> >
> > RiWorldBegin()
> > RiColor(1.0,1.0 ,1.0)
> > RiSurface('cons tant')
> > RiSphere(1.0,-1.0,1.0,360)
> > RiWorldEnd()
> >
> > But I get an error, because python interprets my indentation
> > as a block in the python code. So the only way to write this
> > is without the indentation:
> >
> > RiWorldBegin()
> > RiColor(1.0,1.0 ,1.0)
> > RiSurface('cons tant')
> > RiSphere(1.0,-1.0,1.0,360)
> > RiWorldEnd()
> >
> > But this is a lot harder to read.
> >
> > Is there any way to use such "visual" indentation in python?[/color]
>
> If the code is purely sequential, how about something like this:
>
> import string
> def RunTheseStateme nts(s):
> stmts = map(string.stri p, s.split("\n"))
> for stmt in stmts:
> eval(stmt)
>
> RunTheseStateme nts("""
>
>
> RiWorldBegin()
> RiColor(1.0,1.0 ,1.0)
> RiSurface('cons tant')
> RiSphere(1.0,-1.0,1.0,360)
> RiWorldEnd()
>
>
> """)[/color]

Here's another way -- inside a [..] or (...) construct

[
RiWorldBegin(),
RiColor(1.0,1.0 ,1.0),
RiSurface('cons tant'),
RiSphere(1.0,-1.0,1.0,360),
RiWorldEnd(),
]

Or try this (this might be too ugly)

RiWorldBegin()
if 1:
RiColor(1.0,1.0 ,1.0)
RiSurface('cons tant')
RiSphere(1.0,-1.0,1.0,360)
RiWorldEnd()

or make these all member functions of a class and try

c. RiWorldBegin(),
c. RiColor(1.0,1.0 ,1.0),
c. RiSurface('cons tant'),
c. RiSphere(1.0,-1.0,1.0,360),
c. RiWorldEnd(),

or

Hmmmm -- I'll bet there's more possibilities.

Gary Herron

**Ben Finney** · Jul 18 '05, 01:54 AM

Re: visual indentation

On Fri, 22 Aug 2003 13:06:46 -0700, Gary Herron wrote:[color=blue]
> Hmmmm -- I'll bet there's more possibilities.[/color]

All of which, like all possibilities for forcing different indentation
on Python, presented so far, *reduce* readability instead of enhancing
it.

--
\ "One time a cop pulled me over for running a stop sign. He |
`\ said, 'Didn't you see the stop sign?' I said, 'Yeah, but I |
_o__) don't believe everything I read.'" -- Steven Wright |
Ben Finney <http://bignose.squidly .org/>

**Gary Herron** · Jul 18 '05, 01:54 AM

Re: visual indentation

On Friday 22 August 2003 11:28 am, achrist@easystr eet.com wrote:[color=blue]
> Hilbert wrote:[color=green]
> > Hello,
> >
> > I'm using python to output RIB streams for Renderman.
> > The RIB stream is a bunch of statements which describes
> > a 3d image. The Rib standard allows for blocks which we
> > usually indent for better visualization for example:
> >
> > WorldBegin
> > Color [1 1 1]
> > Surface "constant"
> > Sphere(1.0, -1.0, 1.0, 360)
> > WorldEnd
> >
> > I'm using CGKit in python which has a Renderman binding,
> > so to output the same RIB I'd write:
> >
> > RiWorldBegin()
> > RiColor(1.0,1.0 ,1.0)
> > RiSurface('cons tant')
> > RiSphere(1.0,-1.0,1.0,360)
> > RiWorldEnd()
> >
> > But I get an error, because python interprets my indentation
> > as a block in the python code. So the only way to write this
> > is without the indentation:
> >
> > RiWorldBegin()
> > RiColor(1.0,1.0 ,1.0)
> > RiSurface('cons tant')
> > RiSphere(1.0,-1.0,1.0,360)
> > RiWorldEnd()
> >
> > But this is a lot harder to read.
> >
> > Is there any way to use such "visual" indentation in python?[/color]
>
> If the code is purely sequential, how about something like this:
>
> import string
> def RunTheseStateme nts(s):
> stmts = map(string.stri p, s.split("\n"))
> for stmt in stmts:
> eval(stmt)
>
> RunTheseStateme nts("""
>
>
> RiWorldBegin()
> RiColor(1.0,1.0 ,1.0)
> RiSurface('cons tant')
> RiSphere(1.0,-1.0,1.0,360)
> RiWorldEnd()
>
>
> """)[/color]

Here's another way -- inside a [..] or (...) construct

[
RiWorldBegin(),
RiColor(1.0,1.0 ,1.0),
RiSurface('cons tant'),
RiSphere(1.0,-1.0,1.0,360),
RiWorldEnd(),
]

Or try this (this might be too ugly)

RiWorldBegin()
if 1:
RiColor(1.0,1.0 ,1.0)
RiSurface('cons tant')
RiSphere(1.0,-1.0,1.0,360)
RiWorldEnd()

or make these all member functions of a class and try

c. RiWorldBegin(),
c. RiColor(1.0,1.0 ,1.0),
c. RiSurface('cons tant'),
c. RiSphere(1.0,-1.0,1.0,360),
c. RiWorldEnd(),

or

Hmmmm -- I'll bet there's more possibilities.

Gary Herron

**Dan Bishop** · Jul 18 '05, 01:54 AM

Re: visual indentation

Hilbert <Hilbert@panka. com> wrote in message news:<slrnbkcja 7.s51.Hilbert@s erver.panka.com >...[color=blue]
> Hello,
>
> I'm using python to output RIB streams for Renderman.
> The RIB stream is a bunch of statements which describes
> a 3d image. The Rib standard allows for blocks which we
> usually indent for better visualization for example:
>
> WorldBegin
> Color [1 1 1]
> Surface "constant"
> Sphere(1.0, -1.0, 1.0, 360)
> WorldEnd[/color]
....[color=blue]
> Is there any way to use such "visual" indentation in python?[/color]

If the code consists of nothing but expressions (which yours does), you can write:

(RiWorldBegin() )
( RiColor(1.0,1.0 ,1.0))
( RiSurface('cons tant'))
( RiSphere(1.0,-1.0,1.0,360))
(RiWorldEnd())

or

(
RiWorldBegin(),
RiColor(1.0,1.0 ,1.0),
RiSurface('cons tant'),
RiSphere(1.0,-1.0,1.0,360),
RiWorldEnd()
)

**Skip Montanaro** · Jul 18 '05, 01:54 AM

Re: visual indentation

Hilbert> I'm using CGKit in python which has a Renderman binding, so to
Hilbert> output the same RIB I'd write:

Hilbert> RiWorldBegin()
Hilbert> RiColor(1.0,1.0 ,1.0)
Hilbert> RiSurface('cons tant')
Hilbert> RiSphere(1.0,-1.0,1.0,360)
Hilbert> RiWorldEnd()

Hilbert> But I get an error, because python interprets my indentation as
Hilbert> a block in the python code.

As it should, because whitespace is significant in Python.

Hilbert> So the only way to write this is without the indentation:

Hilbert> RiWorldBegin()
Hilbert> RiColor(1.0,1.0 ,1.0)
Hilbert> RiSurface('cons tant')
Hilbert> RiSphere(1.0,-1.0,1.0,360)
Hilbert> RiWorldEnd()

Hilbert> But this is a lot harder to read.

Hilbert> Is there any way to use such "visual" indentation in python?

In this case, just use "if 1:"

RiWorldBegin()
if 1:
RiColor(1.0,1.0 ,1.0)
RiSurface('cons tant')
RiSphere(1.0,-1.0,1.0,360)
RiWorldEnd()

Skip

**Cliff Wells** · Jul 18 '05, 01:56 AM

Re: visual indentation

On Fri, 2003-08-22 at 11:10, Hilbert wrote:[color=blue]
> Hello,
>
> I'm using python to output RIB streams for Renderman.
> The RIB stream is a bunch of statements which describes
> a 3d image. The Rib standard allows for blocks which we
> usually indent for better visualization for example:
>
> WorldBegin
> Color [1 1 1]
> Surface "constant"
> Sphere(1.0, -1.0, 1.0, 360)
> WorldEnd
>
> I'm using CGKit in python which has a Renderman binding,
> so to output the same RIB I'd write:
>
> RiWorldBegin()
> RiColor(1.0,1.0 ,1.0)
> RiSurface('cons tant')
> RiSphere(1.0,-1.0,1.0,360)
> RiWorldEnd()
>
> But I get an error, because python interprets my indentation
> as a block in the python code. So the only way to write this
> is without the indentation:
>
> RiWorldBegin()
> RiColor(1.0,1.0 ,1.0)
> RiSurface('cons tant')
> RiSphere(1.0,-1.0,1.0,360)
> RiWorldEnd()
>
> But this is a lot harder to read.
>
> Is there any way to use such "visual" indentation in python?[/color]

How about this? It creates a bit of unnecessary overhead (a single
tuple creation), but looks okay visually (and Emacs correctly indents
it):

RiWorldBegin()
(
RiColor(1.0,1.0 ,1.0),
RiSurface('cons tant'),
RiSphere(1.0,-1.0,1.0,360),
)
RiWorldEnd()

Regards,

--
Cliff Wells, Software Engineer
Logiplex Corporation (www.logiplex.net)
(503) 978-6726 (800) 735-0555

**Cliff Wells** · Jul 18 '05, 01:56 AM

Re: visual indentation

On Fri, 2003-08-22 at 11:10, Hilbert wrote:[color=blue]
> Hello,
>
> I'm using python to output RIB streams for Renderman.
> The RIB stream is a bunch of statements which describes
> a 3d image. The Rib standard allows for blocks which we
> usually indent for better visualization for example:
>
> WorldBegin
> Color [1 1 1]
> Surface "constant"
> Sphere(1.0, -1.0, 1.0, 360)
> WorldEnd
>
> I'm using CGKit in python which has a Renderman binding,
> so to output the same RIB I'd write:
>
> RiWorldBegin()
> RiColor(1.0,1.0 ,1.0)
> RiSurface('cons tant')
> RiSphere(1.0,-1.0,1.0,360)
> RiWorldEnd()
>
> But I get an error, because python interprets my indentation
> as a block in the python code. So the only way to write this
> is without the indentation:
>
> RiWorldBegin()
> RiColor(1.0,1.0 ,1.0)
> RiSurface('cons tant')
> RiSphere(1.0,-1.0,1.0,360)
> RiWorldEnd()
>
> But this is a lot harder to read.
>
> Is there any way to use such "visual" indentation in python?[/color]

How about this? It creates a bit of unnecessary overhead (a single
tuple creation), but looks okay visually (and Emacs correctly indents
it):

RiWorldBegin()
(
RiColor(1.0,1.0 ,1.0),
RiSurface('cons tant'),
RiSphere(1.0,-1.0,1.0,360),
)
RiWorldEnd()

Regards,

--
Cliff Wells, Software Engineer
Logiplex Corporation (www.logiplex.net)
(503) 978-6726 (800) 735-0555

**Cliff Wells** · Jul 18 '05, 01:58 AM

Re: visual indentation

On Fri, 2003-08-22 at 11:10, Hilbert wrote:[color=blue]
> Hello,
>
> I'm using python to output RIB streams for Renderman.
> The RIB stream is a bunch of statements which describes
> a 3d image. The Rib standard allows for blocks which we
> usually indent for better visualization for example:
>
> WorldBegin
> Color [1 1 1]
> Surface "constant"
> Sphere(1.0, -1.0, 1.0, 360)
> WorldEnd
>
> I'm using CGKit in python which has a Renderman binding,
> so to output the same RIB I'd write:
>
> RiWorldBegin()
> RiColor(1.0,1.0 ,1.0)
> RiSurface('cons tant')
> RiSphere(1.0,-1.0,1.0,360)
> RiWorldEnd()
>
> But I get an error, because python interprets my indentation
> as a block in the python code. So the only way to write this
> is without the indentation:
>
> RiWorldBegin()
> RiColor(1.0,1.0 ,1.0)
> RiSurface('cons tant')
> RiSphere(1.0,-1.0,1.0,360)
> RiWorldEnd()
>
> But this is a lot harder to read.
>
> Is there any way to use such "visual" indentation in python?[/color]

I'm sending this again as the message I sent earlier apparently never
made it.

RiWorldBegin()
(
RiColor(1.0,1.0 ,1.0),
RiSurface('cons tant'),
RiSphere(1.0,-1.0,1.0,360),
)
RiWorldEnd()

There's a bit of added overhead (superfluous tuple creation) but it does
what you ask.

Regards,
Cliff

--
Should I stand midst the breakers, Should I lie with Death my bride?
-This Mortal Coil

**Hilbert** · Jul 18 '05, 01:58 AM

Re: visual indentation

Thanks for all the suggestions!

I like both the tuple and the if 1: approach.

I don't want to define blocks in functions because that
would actually differ from how the RIB stream works.
I'd like to have my code reflect a real RIB stream.

Thanks again,
Hilbert

hilbert@panka.c om

In article <slrnbkcja7.s51 .Hilbert@server .panka.com>, Hilbert wrote:[color=blue]
> Hello,
>
> I'm using python to output RIB streams for Renderman.
> The RIB stream is a bunch of statements which describes
> a 3d image. The Rib standard allows for blocks which we
> usually indent for better visualization for example:
>
> WorldBegin
> Color [1 1 1]
> Surface "constant"
> Sphere(1.0, -1.0, 1.0, 360)
> WorldEnd
>
> I'm using CGKit in python which has a Renderman binding,
> so to output the same RIB I'd write:
>
> RiWorldBegin()
> RiColor(1.0,1.0 ,1.0)
> RiSurface('cons tant')
> RiSphere(1.0,-1.0,1.0,360)
> RiWorldEnd()
>
> But I get an error, because python interprets my indentation
> as a block in the python code. So the only way to write this
> is without the indentation:
>
> RiWorldBegin()
> RiColor(1.0,1.0 ,1.0)
> RiSurface('cons tant')
> RiSphere(1.0,-1.0,1.0,360)
> RiWorldEnd()
>
> But this is a lot harder to read.
>
> Is there any way to use such "visual" indentation in python?
>
> Thanks,
> Hilbert
>
> hilbert@panka.c om
>
>[/color]

**Hans Nowak** · Jul 18 '05, 01:59 AM

Re: visual indentation

Hilbert wrote:[color=blue]
> Hello,
>
> I'm using python to output RIB streams for Renderman.
> The RIB stream is a bunch of statements which describes
> a 3d image. The Rib standard allows for blocks which we
> usually indent for better visualization for example:
>
> WorldBegin
> Color [1 1 1]
> Surface "constant"
> Sphere(1.0, -1.0, 1.0, 360)
> WorldEnd
>
> I'm using CGKit in python which has a Renderman binding,
> so to output the same RIB I'd write:
>
> RiWorldBegin()
> RiColor(1.0,1.0 ,1.0)
> RiSurface('cons tant')
> RiSphere(1.0,-1.0,1.0,360)
> RiWorldEnd()
>
> But I get an error, because python interprets my indentation
> as a block in the python code. So the only way to write this
> is without the indentation:
>
> RiWorldBegin()
> RiColor(1.0,1.0 ,1.0)
> RiSurface('cons tant')
> RiSphere(1.0,-1.0,1.0,360)
> RiWorldEnd()
>
> But this is a lot harder to read.
>
> Is there any way to use such "visual" indentation in python?[/color]

I can think of various ugly solutions, none of them very satisfying...

First, you can fake an indented block, e.g. like this:

RiWorldBegin()
if 1:
RiColor(1.0, 1.0, 1.0)
# etc...
RiWorldEnd()

Or you can put the function calls in a dummy list/tuple:

RiWorldBegin()
[
RiColor(1.0, 1.0, 1.0),
RiSurface('cons tant'),
RiSphere(1.0,-1.0,1.0,360),
]
RiWorldEnd()

Or you can put some dummy statements in front...

RiWorldBegin()
(); RiColor(1.0, 1.0, 1.0)
(); RiSurface('cons tant')
(); RiSphere(1.0,-1.0,1.0,360)
RiWorldEnd()

I warned you they were ugly... :-)

Maybe the best solution would be judicious use of comments, e.g.

RiWorldBegin()
#
RiColor(1.0, 1.0, 1.0)
RiSurface('cons tant')
RiSphere(1.0,-1.0,1.0,360)
#
RiWorldEnd()

This doesn't give you indentation, but at least the statements in the "block"
stand out more.

But maybe somebody else has a better solution...?

--
Hans (hans@zephyrfal con.org)

zephyrfalcon.org

http://zephyrfalcon.org/

Memimpin Angin Perubahan Teknologi

**Evan Simpson** · Jul 18 '05, 01:59 AM

Re: visual indentation

Hilbert wrote:[color=blue]
> RiWorldBegin()
> RiColor(1.0,1.0 ,1.0)
> RiSurface('cons tant')
> RiSphere(1.0,-1.0,1.0,360)
> RiWorldEnd()
>
> Is there any way to use such "visual" indentation in python?[/color]

If all of the lines that you want to indent in this fashion are
expressions, not statments, then you could do this:

RiWorldBegin()
( RiColor(1.0,1.0 ,1.0) )
( RiSurface('cons tant') )
( RiSphere(1.0,-1.0,1.0,360) )
RiWorldEnd()

If there are statements involved, you could do this:

RiWorldBegin()
1; RiColor(1.0,1.0 ,1.0)
1; RiSurface('cons tant')
1; RiSphere(1.0,-1.0,1.0,360)
RiWorldEnd()

Both are ugly, of course.

Cheers,

Evan @ 4-am

visual indentation

visual indentation

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