[Python-Dev] Breaking undocumented API

[Greg Ewing]

Stephen J. Turnbull wrote:
> I don't really understand
> what Tres is talking about when he writes "modules that expect to be
> imported this way".  The *imported* module shouldn't care, no?  This
> is an issue for the *importing* code to deal with.

I think he's talking about modules that add a prefix to all
of their exported names, such as Tkinter starting everything
with "Tk", on the expectation that import * will be the normal
way of using the module.

For very well-known modules with very well-known prefixes,
this probably doesn't do too much harm, since it's usually
fairly obvious where a given name is coming from. However,
it's probably best not encouraged, as it could lead people
who don't know better into bad habits.

There's also the downside that people who choose *not* to
use import *, and instead import the module itself and use
qualified references, end up with everything being prefixed
twice, e.g. 'import Tkinter as tk' leads to 'tk.TkWhatever'
everywhere.

On the other hand, when wrapping a C library there's a desire
to keep the Python names as close as possible to the C ones,
which usually come with prefixes to manage C's totally-global
namespace. So there's a bit of a double bind there.

-- 
Greg