Re: [PATCH RFC 01/32] python/qemu: create qemu.lib module

[John Snow <jsnow@redhat.com>]

On 5/18/20 2:14 PM, Vladimir Sementsov-Ogievskiy wrote:
> 14.05.2020 08:53, John Snow wrote:
>> move python/qemu/*.py to python/qemu/lib/*.py.
>>
>> To create a namespace package, the 'qemu' directory itself shouldn't
>> have module files in it. Thus, these files will go under a 'lib' package
>> directory instead.
> 
> Hmm..
> 
> On the first glance, it looks better to have
> 
>   from qemu import QEMUMachine
> 
> than
>  
>   from qemu.lib import QEMUMachine
> 
> why do we need this extra ".lib" part?
> 
> Is it needed only for internal use?
> 
> Assume we have installed qemu package. Can we write
> 
>   from qemu import QEMUMachine
> 
> ? Or we still need qemu.lib ?
> 
> I don't remember any python package, which made me to write "import from
> package_name.lib ..."
> 
> 

It's a strategy to create "qemu" as a PEP420 namespace package; i.e.
"qemu" forms a namespace, but you need a name for the actual package
underneath it.

"qemu.lib" is one package, with qmp, qtest, and machine modules. "qemu"
isn't really a package in this system, it's just a namespace.

The idea is that this allows us to create a more modular rollout of
various python scripts and services as desired instead of monolithically
bundling them all inside of a "qemu" package.

It also allows us to fork or split out the sub-packages to separate
repos, if we wish. i.e., let's say we create a "qemu.sdk" subpackage, we
can eventually fork it off into its own repo with its own installer and
so forth. These subpackages can be installed and managed separately.