strange import phenomenon

[Dieter Maurer]

Christoph Zwerschke <cito at online.de> writes on Tue, 20 Sep 2005 11:20:37 +0200:
> Just hitting a strange problem with Python import behavior. It is the
> same on all Python 2.x versions and it is probably correct, but I
> currently don't understand why this happens.
> ...
> --- dir/__init__.py ---
> print "init"
> -----------------------
> 
> 
> --- dir/hello.py ------
> print "hello world"
> -----------------------
> 
> 
> --- dir/test2.py ------
> import sys
> sys.path = []
> 
> import hello
> -----------------------
> 
> 
> The script test2.py removes all entries from the sys.path. So when I
> run test2.py directly, I get an ImportError because the hello module
> cannot be imported. This is as expected.
> 
> 
> However, if I run test1, the hello module *is* imported and I get the
> "hello world" message. Why is that??

Because Python tries to resolve modules inside a package ("dir" in
your example) locally first. This local resolution does not
involve "sys.path" but "package.__path__".
Only when the local lookup fails, a global lookup (using "sys.path")
is tried.

In your case, the local lookup succeeds.


Dieter