[Python-Dev] Fix import errors to have data
bac at OCF.Berkeley.EDU
Wed Jul 28 01:58:02 CEST 2004
Neal Norwitz wrote:
> On Tue, Jul 27, 2004 at 12:39:22PM -0400, Jim Fulton wrote:
>>Tim Peters wrote:
>>>>No, it won't. For example, suppose foo imports B. B tries to import
>>>>C, but fails. B is now broken, but it is still importable. Actually,
>>>>both foo and B can be imported without errors, even though they are
>>>Then you're proposing a way for a highly knowledgable user to
>>>anticipate, and partially worm around, that Python leaves behind
>>>insane module objects in sys.modules.
>>No. I'm proposing a way for a Python developer to detect the
>>presence or absence of a module.
>>Hm, perhaps it would be better to provide an API (if there isn't one
>>already) to test whether a module is present.
> Another possibility could be to add a ChainedImportError (or
> SubImportError?) which would derive from ImportError. The module
> which imports a broken module would get the normal ImportError. If
> the module doesn't catch the exception, it would get converted to this
> new type of ImportError.
> I don't know how easy this would be to implement, but I think it
> would solve Jim's problem and perhaps be easier to deal with?
Having exceptions keeping track of previous exceptions might also work.
I know that idea was brought up before last year (see
for the historically accurate summary of the thread). Idea died when no
one could come up with a good way of storing previous exception info.
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