[Python-Dev] Re: [Pythonmac-SIG] The versioning question...

[Eric Nieuwland]

Martin v. Löwis wrote:
> Eric Nieuwland wrote:
>> Would it be an idea to submit a PEP for extending the 'import' 
>> keyword?
>
> No. Normally, packages should aim for backwards compatibility, so that
> applications would only want to specify a minimum version, such as
>
> import xml
> assert xml.version_info > (0,8,2)
>
> If you really want side-by-side installation of different versions,
> and a mechanism to select between them, the package could support
>
> import xml_0_8_2 as xml
>
> IOW, "import-as" should be sufficient for what you want to achieve.

Unless you are doing comparison tests, where it would be nice to be 
able to state in a generic way that the new implementation should not 
change answers. May be something like:

import spam[1] as spamnext		# next version
import spam[0]	as spamnow		# current version

assert spamnow.Ni() == spamnext.Ni()

--eric