[Distutils] namespace_packages: include itself ot not include
rik at inse.ru
Tue Feb 8 20:29:42 CET 2011
Sorry for top-posting. Since my model was braked, I'll try to explain the
problem from very beginning. I didn't expect that model is totally wrong :-)
There is a package 'aaa.bbb' that uses setuptool only if it is installed on
the system. This is useful for development, but this breaks rpm build
process cause it expects __init__.py and doesn't expect egg and pth,
more over it ignores them. So in my case there is no egg & pth.
I started to dig if there is possibility to coexists development and
processes on the same system without very messy spec file. I didn't find
the strict requirements for the package to list itself in a
even if I know that there would be 'aaa.bbb.ccc'. But if I not list it
can ignore egg&pth files, and in my cases setuptool will behave compatible.
So probably question does it break something if package 'aaa.bbb'
wouldn't list itself in a namespace_package? And does it provide something
useful if package 'aaa.bbb' would?
P.J. Eby wrote:
> At 01:07 PM 2/8/2011 +0300, Roman Kurakin wrote:
>> P.J. Eby wrote:
>>> At 12:06 AM 2/8/2011 +0300, Roman Kurakin wrote:
>>>> but one is initial provider of 'aaa' share
>>>> and other consumer of 'aaa' share.
>>> This statement is why you're confused. A namespace is not
>>> "provided" by anyone, only participated in.
>> No I am confused by practice :-) . The problem I am thinking about is
>> So __init__.py is my namespace provider I thinking of beside the scene.
> There is no such thing as a namespace provider. That's why you're
> confused. A namespace package is just a namespace for other modules
> and packages. It does not have any existence of its own.
>> problem I hit was with rpm packages I was playing with. The package
>> list itself in namespace_packages and developer states that this is
>> needed cause
>> there is 'aaa.bbb.ccc' package. In this case, installer drops
>> __init__.py not only
>> for aaa/__init__.py but also for aaa/bbb/__init__.py. For 'aaa' this
>> is correct
>> since some one should provide __init__.py for 'aaa' before us.
> You're still confused. In the RPM case, there will be *no*
>> But who will
>> provide __init__.py for 'aaa.bbb' if we pack it as setuptool provided
>> it for us?
> It is not necessary. Look for a file like
> "mypackage-version-nspkg.pth" in the directory adjacent to aaa -- you
> will see that it contains code to make the package exist despite the
> nonexistence of the __init__.py
>>> Think of it this way. You and I decide to have lunch together. I
>>> am not providing the lunch. You are not providing the lunch. But
>>> we are both participating in the lunch.
>>> That is how namespace packages work. aaa.bbb participates in the
>>> aaa namespace, therefore it lists aaa as a namespace package.
>> But what about 'aaa.bbb' that lists itself as a namespace package?
> You are saying, "but what if I provide the lunch?" You can't provide
> the lunch. You can only *join* the lunch.
> You are trying to solve a problem that doesn't exist. Namespace
> packages are the names of a *group* of modules or packages. There is
> no "main" package for a namespace, and no "extensions". There is no
> single project that "provides" the namespace, just like there is no
> one person who "provides" the lunch.
> If you persist in thinking that there is a provider, then you will
> continue to be confused, and trying to solve a problem that doesn't
> actually exist.
>> Should it list itself or not? In case it should, the question is how to
>> deal with __init__.py?
> As it says in the setuptools documentation, you must provide an
> __init__.py in your project that ONLY contains the namespace
> registration. In installation environments that do not require an
> __init__.py (e.g. rpm installs), this file will NOT be included -- an
> nspkg.pth file will be used instead. For .egg files and directories,
> the __init__.py of every participating project is included, but only
> the first one found on sys.path will actually be used.
>> That is why I tried to draw such model with providers and extenders.
>> One should make reservation if lunch is planned in some popular place.
> Setuptools handles the reservations. The project simply says, "I'm
> with the aaa group", and setuptools says, "ah, then you're sitting
> over here". ;-) If there is nobody else arrived yet, then setuptools
> takes care of allocating the table, so to speak, and then seats all
> the newcomers there as well.
> But, just because one person arrives first, doesn't make them the head
> of the group. Members of the party may arrive in any order, and when
> others show up they will be seated in the same place.
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