[Python-Dev] New relative import issue (original) (raw)

Giovanni Bajo rasky at develer.com
Thu Sep 21 15:05:38 CEST 2006

Oleg Broytmann wrote:

There really shouldn't be any such thing as sys.path -- the view that any given module has of the package namespace should depend only on where it is I do not understand this. Can you show an example? Imagine I have two servers, Linux and FreeBSD, and on Linux python is in /usr/bin, home is /home/phd, on BSD these are /usr/local/bin and /usr/home/phd. I have some modules in site-packages and some modules in $HOME/lib/python. How can I move programs from one server to the other without rewriting them (how can I not to put full paths to modules)? I use PYTHONPATH manipulation - its enough to write a shell script that starts daemons once and use it for many years. How can I do this without sys.path?!

My idea (and interpretation of Greg's statement) is that a module/package should be able to live with either relative imports within itself, or fully absolute imports. No sys.path hackery should ever be necessary to access modules in sibling namespaces. Either it's an absolute import, or a relative (internal) import. A sibling import is a symptom of wrong design of the packages.

This is how I usually design my packages at least. There might be valid use cases for doing sys.path hackery, but I have yet to find them.

Giovanni Bajo

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