Import arbitrary subdirectory modules

Question

Present situation:

I have a script: program.py.
I have a directory: /imports. Which contains an arbitrary amount of modules in subdirectories.

Python's package directory syntax is being used.

 __init__.py
 program.py
 /imports
     __init__.py
     /module a
         __init__.py
         other_files.py
     /module b
         __init__.py
         other

Intention:

program.py should import every subdirectory in /imports.
program.py needs object access to the modules. For example, imports['name'].Service().

Remark: I don't feel like illustrating my purpose or questioning the design choice. I'm using the above workaround. The problem is described below.

The existing code:

import os

modules = []
IMPORT_PATH = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'imports')
to_import = [name for name in os.listdir(IMPORT_PATH) if os.path.isdir(os.path.join(IMPORT_PATH, name))]
modules = [__import__('imports.' + x) for x in to_import]
print modules

Output:

[<module 'imports' from '/code/test/imports/__init__.pyc'>, <module 'imports' from '/code/test/imports/__init__.pyc'>]

Desired output:

[<module 'B' from '/code/test/imports/B'>, <module 'C' from '/code/test/imports/C'>]

Use [`__import__`](https://docs.python.org/3/library/functions.html#__import__) — Konstantin, Jul 30 '15 at 10:10
import x wouldn't work because import doesnt take a variable. Try `__import__` or using `importlib.import_module` — muddyfish, Jul 30 '15 at 10:10

score 2 · Accepted Answer · edited May 23 '17 at 12:02

Problem identified: The fromlist=[] argument for __import__() is missing. See Why does Python's __import__ require fromlist? for elaboration.

Corrected example:

modules = {}
IMPORT_PATH = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'imports')
to_import = [name for name in os.listdir(IMPORT_PATH) if os.path.isdir(os.path.join(IMPORT_PATH, name))]
for x in to_import:
    modules[x] = __import__('imports.' + x, fromlist=['*'])

Output:

{'C': <module 'imports.C' from '/code/test/imports/C/__init__.pyc'>, 
'B': <module 'imports.B' from '/code/test/imports/B/__init__.pyc'>}

Achieved result:

Now modules[dir_name].Service() can be used in program.py.

Import arbitrary subdirectory modules

1 Answers1