Sorry for the generic title, will change it once I understand the source of my problem
I have the following structure:
foo/
foo/__init__.py
foo/bar/
foo/bar/__init__.py
foo/bar/some_module.py
When I try to import some_module by doing so:
from foo.bar import some_module
it works like a charm.
But this is no good for me, since I only know the name of the module to import in runtime. so if I try:
from foo.bar import *
mod=__import__('some_module')
I get an error. Am I doing something wrong? Is there a better way to do this? and why is this happening?
Why is that? I am not quite sure I completely understand the concept behind python packages. I thought they were equivalent to java's packages and thus
I believe the proper way to do this is:
mod = __import__('foo.bar', fromlist = ['some_module'])
This way even the 'foo.bar' part can be changed at runtime.
As a result some_module
will be available as mod.some_module
; use getattr if you want it in a separate variable:
the_module = getattr(mod, 'some_module')
from foo.bar import *
is a bad practice since it imports some_module
into the global scope.
You should be able to access your module through:
import foo.bar
mod = getattr(foo.bar, 'some_module')
It can be easily demonstrated that this approach works:
>>> import os.path
>>> getattr(os.path, 'basename')
<function basename at 0x00BBA468>
>>> getattr(os.path, 'basename\n')
Traceback (most recent call last):
File "<pyshell#31>", line 1, in <module>
getattr(os.path, 'basename\n')
AttributeError: 'module' object has no attribute 'basename
'
P.S. If you're still interested in using your kind of import statement. You need an eval
:
from foo.bar import *
eval('some_module')
To clarify: not only it's bad practice to use *
-import it's even worse in combination with eval
. So just use getattr
, it's designed exactly for situations like yours.
From the docs:
Direct use of __import__()
is rare, except in cases where you want to import a module whose name is only known at runtime.
However, the dotted notation should work:
mod = __import__('foo.bar.some_module')