"from A import B.C" in Python?

Question

In Python, it is possible to import dotted submodules explicitly:

import os.path

makes os.path available.

Now, is there a simple way to do the same thing for sub-submodules? The following code (which does not work) illustrates what I am looking for:

from A import B.C
from A import B.D

(from A import B does not import B.C and B.D, for the module A.B that I need to use). I would like to do this because:

• I prefer to not pollute the main namespace with C and D (from A.B import C, D) because they do not have very specific names.
• I would like to keep the sub-submodules inside their B namespace (for the same reason).

One solution is to do:

from A import B
from A.B import C, D
del C, D

which loads and defines B.C and B.D. However, this is (1) quite unusual, (2) somewhat obscure (side effect of defining B.C and B.D) and (3) maybe with a result that's not guaranteed (will B.C and B.D always be defined with this code?).

Is this method of putting only B.C and B.D (and B) in the namespace acceptable? is there a better method? maybe it actually best to find some legible compromise like from A.B import C as B_C, D as B_D?

While I am stuck with Python 2.6 (no importlib module…), for this problem, I am also curious about any modern solution.

Answer 1

importlib can help here

import importlib
from A import B
importlib.import_module('A.B.C')
importlib.import_module('A.B.D')
# Now you can use B.C & B.D

On Python2.6 you should be able to

from A import B
import A.B.C
import A.B.D
del A

Answer 2

For the intent of from A import B.C, I would suggest doing this:

from A.B import C as B_C

Answer 3

One of the cleanest ways is to do what Jayanth mentioned. If A is a long name then you can rename using the 'as' keyword

import A as X