Hi all
I thought I was getting the hang of circular imports, but after upgrading to
python 3.2 I am stumped again. I know some people think that circular
imports are always bad, but others suggest that, provided you understand the
potential problems, they can be acceptable.
Assume the following structure -
main.py
/pkg
__init__.py
mod1.py
mod2.py
main.py
from pkg import mod1
mod1.py
import mod2
mod2.py
import mod1
Using python 2.6, running main.py works.
After running 2to3.py on the above directory, mod1.py was changed to 'from .
import mod2' and mod2.py was changed to 'from . import mod1'.
With python 3.2, it now fails with the following traceback -
Traceback (most recent call last):
File "main.py", line 1, in <module>
from pkg import mod1
File "pkg\mod1.py", line 1, in <module>
from . import mod2
File "pkg\mod2.py", line 1, in <module>
from . import mod1
ImportError: cannot import name mod1
I have read the relevant peps and various other material, understood them to
a certain extent, tried several alternatives, but could not find a solution.
I have found a hack that works, but I don't like it very much. I added the
following to '__init__.py' -
import os
import sys
sys.path.insert(0, os.path.dirname(__file__))
This adds the package name into the search path.
Then I changed mod1.py and mod2.py back to the original 'import mod2' and
'import mod1'.
It works, but it seems to be defeating the purpose of PEP 328, which I
thought was an improvement.
Any comments or suggestions will be appreciated.
Frank Millman
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