Docstrings for class attributes

[Tom Harris]

Greetings,

I want to have a class as a container for a bunch of symbolic names
for integers, eg:

class Constants:
FOO = 1
BAR = 2

Except that I would like to attach a docstring text to the constants,
so that help(Constants.FOO) will print some arbitrary string. Sort of
a very limited implementation of PEP 224. The only solution that I can
see is to subclass int.__new__(), since once I have an int all it's
attributes are immutable.

--

Tom Harris <celephicus(AT)gmail(DOT)com>

[Bruno Desthuilliers]

Tom Harris a écrit :

Greetings,

I want to have a class as a container for a bunch of symbolic names
for integers, eg:

class Constants:
FOO = 1
BAR = 2

Do you have a reason to stuff them in a class ? Usually, putting them at
the top level of a module is quite enough...

Except that I would like to attach a docstring text to the constants,
so that help(Constants.FOO) will print some arbitrary string.

You can document them in the module or class docstring...

[Diez B. Roggisch]

Tom Harris wrote:

Greetings,

I want to have a class as a container for a bunch of symbolic names
for integers, eg:

class Constants:
FOO = 1
BAR = 2

Except that I would like to attach a docstring text to the constants,
so that help(Constants.FOO) will print some arbitrary string. Sort of
a very limited implementation of PEP 224. The only solution that I can
see is to subclass int.__new__(), since once I have an int all it's
attributes are immutable.

Epydoc interprets strings like this as doc-strings:

"""
FOO is not a bar
"""
FOO = "foo"
However, it won't get recognized by help of course.

Diez

[Peter Pearson]

On Tue, 23 Sep 2008 15:23:35 +1000, Tom Harris <ce********@gmail.comwrote:

>
I want to have a class as a container for a bunch of symbolic names
for integers, eg:

class Constants:
FOO = 1
BAR = 2

Except that I would like to attach a docstring text to the constants,
so that help(Constants.FOO) will print some arbitrary string.

[snip]

Commiserating, not helping: I have a similar problem with a module
that holds values of physical constants,
http://webpages.charter.net/curryfans/peter/nature.py:

boltzmanns_constant = 1.380622e-16 * erg / k
stefan_boltzmann_constant = 5.66961e-5 * erg/s/cm/cm/k/k/k/k
gravitational_constant = 6.6732e-8 * erg*cm/g/g

I would like to reveal more details with, e.g.,
help( gravitational_constant ) . . . and maybe then I could
use shorter names.

--
To email me, substitute nowhere->spamcop, invalid->net.

[Terry Reedy]

Peter Pearson wrote:

On Tue, 23 Sep 2008 15:23:35 +1000, Tom Harris <ce********@gmail.comwrote:

>I want to have a class as a container for a bunch of symbolic names
for integers, eg:

class Constants:
FOO = 1
BAR = 2

Except that I would like to attach a docstring text to the constants,
so that help(Constants.FOO) will print some arbitrary string.

[snip]

Commiserating, not helping: I have a similar problem with a module
that holds values of physical constants,
http://webpages.charter.net/curryfans/peter/nature.py:

boltzmanns_constant = 1.380622e-16 * erg / k
stefan_boltzmann_constant = 5.66961e-5 * erg/s/cm/cm/k/k/k/k
gravitational_constant = 6.6732e-8 * erg*cm/g/g

I would like to reveal more details with, e.g.,
help( gravitational_constant ) . . . and maybe then I could
use shorter names.

gravitational_constant = g = 6.6732e-8 * erg*cm/g/g
....

[Steven D'Aprano]

On Tue, 23 Sep 2008 15:23:35 +1000, Tom Harris wrote:

Greetings,

I want to have a class as a container for a bunch of symbolic names for
integers, eg:

class Constants:
FOO = 1
BAR = 2

Except that I would like to attach a docstring text to the constants, so
that help(Constants.FOO) will print some arbitrary string. Sort of a
very limited implementation of PEP 224. The only solution that I can see
is to subclass int.__new__(), since once I have an int all it's
attributes are immutable.

Others have suggested solutions, which may be better, but for
completeness consider using properties:

def make_const(value, doc=''):
def getter(self):
return value
return property(getter, None, None, doc)
class Foo(object):
x = make_const(1.234, 'a special number')
The only gotcha is that while help(Foo.x) works, help(Foo().x) does not.
--
Steven