from __future__ import absolute_import issue

Gabriel Genellina gagsl-py2 at
Sat May 23 21:39:09 EDT 2009

En Sat, 23 May 2009 12:32:24 -0300, LittleGrasshopper  
<seattlehanks at> escribió:

> On May 22, 12:42 am, "Gabriel Genellina" <gagsl-... at>
> wrote:
>> En Wed, 20 May 2009 20:18:02 -0300, LittleGrasshopper  
>> <seattleha... at> escribió:
>> > It appears that either absolute imports (or my brain) aren't working.
>> > Given a module which is in the same directory as
>> > #File
>> > from __future__ import absolute_import
>> > import string
>> > print string # Module imported is in current directory, not
>> > standard library module
>> absolute_import helps with imports inside a package (those are  
>> "relative"  
>> imports, relative to the package). If a module is located in a  
>> directory  
>> listed in sys.path, an absolute import will find it. I don't think  
>> there  
>> is a way to avoid shadowing a standard module (other than ensuring the  
>> standard directories come first in sys.path).
> You are right. If you have a directory in your PYTHONPATH before the
> standard library directories that has a string module, for example,
> absolute_import will not help you. I was getting confused by the fact
> that when I print sys.path from the python shell, the first entry is
> an empty string.
> This empty string must denote the current directory though, because:
> ['', '/usr/lib/', '/usr/lib/python2.5', '/usr/lib/ ...]
> When I have this sys.path, doing an "import string" from a module
> where I have absolute imports enabled will still import the string
> module in the package (which also means it is in the same directory in
> this case.)

Mmm, I don't understand this. Do you mean that the current directory is a  
package (that is, it contains an file? And the main script is  
there? Then, from Python's POV, it is NOT a package; packages are  
recognized only at import time; if you execute a script that happens to be  
inside a package directory, Python is not aware of the "packageness" of  
such directory.
In that case, all imports are absolute.
The current directory should not be a package (at least, not a package  
accessible from sys.path), nasty things may happen.

> So I think my is being imported not because it
> is in the same package, but because the home directory is searched
> first.


> The empty string doesn't make much sense though (at least in a
> Unix system, you would imagine it would be something like './') but I
> guess that synce Python is platform independent, the empty string is
> taken to denote the current directory.

Maybe you're surprised, but I don't think it's strange at all. Nobody  
writes open("./foo.txt") instead of open("foo.txt"), and  
os.path.normpath("./foo.txt") is actually "foo.txt". Having no path  
specification means "use the current directory" (at least in all OS that I  
know of, where "process' current directory" makes any sense)

Gabriel Genellina

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