[SciPy-dev] More bugs fixed

[Pearu Peterson]

On Sun, 9 Oct 2005, Arnd Baecker wrote:

>>> When only "scipy core" is installed,
>>> scipy.linalg will just contain the basic routines,
>>> and use lapack_lite (and possibly no dotblas etc.).
>>>
>>> When also "scipy full" is installed, scipy.linalg will
>>> have the full glory of all the routines provided in present scipy.
>>>
>>> Technically the question is if there is
>>> a way to achieve this without "scipy full" overwriting
>>> files from "scipy core" (thinking of .deb/.rpm/... packages).
>>>
>>> Does this sound reasonable and feasible?
>>
>> Reasonable, yes. Feasible, not really, I don't think. At the moment, the
>> scipy_core versions are "physically" under scipy.basic. In
>> scipy/__init__.py, we have a block like this:
>>
>>     import scipy.basic.fft as fftpack
>>     import scipy.basic.linalg as linalg
>>     import scipy.basic.random as random
>>
>> So "from scipy import linalg" should work even with scipy_core. I'm not
>> entirely sure if this is going to continue to work in the various
>> situations where you can't overwrite stuff,
>
>
> Would something like
>
>    try:
>        import scipy.THE_FULL_ONE.fft as fftpack
>        import scipy.THE_FULL_ONE.linalg as linalg
>        import scipy.THE_FULL_ONE.random as random
>    except ImportError:
>        import scipy.basic.fft as fftpack
>        import scipy.basic.linalg as linalg
>        import scipy.basic.random as random
>
> work?
> This assumes that the routines from
> `THE_FULL_ONE` are compatible with the `basic` ones.

It would probably work but it is a bad idea as it assumes that packages 
are are always bug-free, which is not true in real world.

IMO any try-except block should be implemented so that it always behaves 
according to the meaning when the try-except block was introduced. So, 
try-except blocks should be very minimal both in code as well as in 
action.

Anyway, I would suggest implementing scipy/__init__.py such that it would 
not require modifications when a new Scipy package has been included.
So, it means that the __init__.py files should recognize somehow which 
scipy subdirectories are SciPy packages and then import them + update 
documentations and test suites. This was 
implemented in Scipy 0.3 Lib/__init__.py file, see the _import_packages() 
function, for Scipy 0.4 it may require some revision though.

Pearu