I really hope this is a simple case of me miss-understanding the complex Python2 import mechanisms. I have the following setup:
$> ls -ltr pypackage1
total 3
-rw-r--r-- 1 pelson pelson 0 Aug 17 19:20 io.py
-rw-r--r-- 1 pelson pelson 0 Aug 17 19:20 __init__.py
-rw-r--r-- 1 pelson pelson 57 Aug 17 19:22 code.py
$> cat pypackage1/code.py
from __future__ import absolute_import
import zipfile
ie I have nothing but a stub package with an empty __init__.py
and io.py
, and a 2 lines code.py
file.
I can import pypackage1
:
$> python -c "import pypackage1.code"
But I cannot run the code.py
file:
$> python pypackage1/code.py
Traceback (most recent call last):
File "pypackage1/code.py", line 3, in <module>
import zipfile
File "python2.7/zipfile.py", line 462, in <module>
class ZipExtFile(io.BufferedIOBase):
AttributeError: 'module' object has no attribute 'BufferedIOBase'
Clearly the problem has to do with the zipfile
module picking up my relative io module over the builtin io
module, but I thought my from __future__ import absolute_import
would have fixed that.
Thanks in advance for any help,
That's the correct behaviour. If you want to fix the error simply do not run from inside the package.
When you run a script which is inside the package, python wont interpret that directory as a package, thus adding the working directory to the PYTHONPATH
. That's why the io
module imported by the zipfile
module is your io
module and not the one inside the standard library.
I'd recommend to create a simple launcher script outside your package (or in a bin/scripts
folder), and launch that. This script can simply contain something like:
from pypackage1 import code
code.main()
An alternative to this is to tell the python interpreter that the file that you want to execute is part of a module. You can do this using the -m
command line option. In your case you would have to do:
python -m pypackage1.code
Note that the argument of -m
should be the module name , not the file name.
One solution would be to put from __future__ import absolute_import
in the zipfile.py
module. Although your module is using absolute import, the zipfile module is not.
Another option is to not run from your package directory. You probably shouldn't be running the interpreter from within the package directory.
File structure:
test.py
mylib/__init__.py
mylib/__collections.py
mylib/collections.py
mylib/mymod.py
This solution allows for:
In test.py:
from collections import deque
from mylib.collections import mydict
In mylib/__init__.py:
from __future__ import absolute_import
from . import collections
from . import mymod
In mylib/__collections.py:
class MyDict (dict):
pass
In mylib/collections.py:
from __collections import *
In mylib/mymod.py:
from __future__ import absolute_import
from collections import deque
try:
# Module running as part of mylib
from .collections import MyDict
except ValueError:
# Module running independently
from __collections import MyDict
The above works with Python >=2.5. Python 3 doesn't need the lines 'from __future__ import absolute_import'.
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