relative import broken?

[Alan Isaac]

Are relative imports broken in 2.5?
Directory ``temp`` contains::

__init__.py
test1.py
test2.py

File contents:
__init__.py and test2.py are empty
test1.py contains a single line::

from . import test2

Python 2.5.1 under Win2000, cmd line execution,
produces as output::

Traceback (most recent call last):
File "F:\temp\test1. py", line 1, in <module>
from . import test2
ValueError: Attempted relative import in non-package

Why?

Thanks,
Alan Isaac

[Alan Isaac]

"Alex Martelli" <al***@mac.comw rote in message
news:1h******** *************** ****@mac.com...

So what do you think the answer should be?

Well I'm clearly not seeing into the depths of this,
so I'm not going to propose anything. But to stick
close to my example, I am not clear why a script
when executed could not do imports relative to
__file__. This seems like natural behavior to me.

Thanks,
Alan Isaac

[Alan Isaac]

"Alex Martelli" <al***@mac.comw rote in message
news:1h******** *************** **@mac.com...

Very simply, PEP 328 explains:
"""
Relative Imports and __name__

Relative imports use a module's __name__ attribute to determine that
module's position in the package hierarchy. If the module's name does
not contain any package information (e.g. it is set to '__main__') then
relative imports are resolved as if the module were a top level module,
regardless of where the module is actually located on the file system.
"""

To change my question somewhat, can you give me an example
where this behavior (when __name__ is '__main__') would
be useful for a script? (I.e., more useful than importing relative
to the directory holding the script, as indicated by __file__.)

Thanks,
Alan Isaac

[Leo Kislov]

On May 3, 10:08 am, "Alan Isaac" <ais...@america n.eduwrote:

"Alex Martelli" <[e-mail] ote in message

news:1h******** *************** **@mac.com...

Very simply, PEP 328 explains:
"""
Relative Imports and __name__

Relative imports use a module's __name__ attribute to determine that
module's position in the package hierarchy. If the module's name does
not contain any package information (e.g. it is set to '__main__') then
relative imports are resolved as if the module were a top level module,
regardless of where the module is actually located on the file system.
"""

To change my question somewhat, can you give me an example
where this behavior (when __name__ is '__main__') would
be useful for a script? (I.e., more useful than importing relative
to the directory holding the script, as indicated by __file__.)

Do you realize it's a different behaviour and it won't work for some
packages? One possible alternative is to assume empty parent
package and let from . import foo work but not
from .. import bar or any other upper levels. The package author
should also realize __init__.py will be ignored.

-- Leo