on Thu Jun 21 2007, Ben Finney <bignose+hates-spam-AT-benfinney.id.au> wrote:
> David Abrahams <[EMAIL PROTECTED]> writes: > >> I'm pretty comfortable with Python, but recently I'm constantly >> finding mysterious issues with import. For example, looking at >> >> http://genshi.edgewall.org/browser/trunk/genshi/filters/transform.py >> >> the examples use the symbol 'HTML' but it's not defined locally, it's >> not explicitly imported, and there's no import *. Yet doctest will >> test this module and it passes with flying colors. It turns out HTML >> is defined in genshi.input. How do I know that? I grepped for it. >> How does it become available to this module? > > That's a mystery to me too. I can't see by looking at the module where > this 'HTML' name comes from, and as you say there is no import of > 'genshi.input'. > > Whatever the explanation, it's a violation of one of the strengths of > Python: namespaces. Names that appear in the current namespace (as > happens with 'from foo import *', and as seems to be happening here) > are bad programming style, for exactly the reason that they make the > code more difficult to understand. Sometimes that's true, but I disagree with it as a general rule. Some bindings are idiomatic, in widespread use throughout a project, and would look dumb and make the code too verbose and hard-to-understand if qualified (especially if fully qualified). The practice may make it harder to understand when something goes wrong, but that's a separate issue. -- Dave Abrahams Boost Consulting http://www.boost-consulting.com The Astoria Seminar ==> http://www.astoriaseminar.com -- http://mail.python.org/mailman/listinfo/python-list
