How to import a module in Python with importlib.import_module

Question

I'm trying to use importlib.import_module in Python 2.7.2 and run into the strange error.

Consider the following dir structure:

     a     |     + - __init__.py       - b         |         + - __init__.py           - c.py 

a/b/__init__.py has the following code:

     import importlib      mod = importlib.import_module("c") 

(In real code "c"has a name.)

Trying to import a.b, yields the following error:

     >>> import a.b     Traceback (most recent call last):       File "", line 1, in        File "a/b/__init__.py", line 3, in          mod = importlib.import_module("c")       File "/opt/Python-2.7.2/lib/python2.7/importlib/__init__.py", line 37, in   import_module         __import__(name)     ImportError: No module named c 

What am I missing?

Thanks!

Answer 1

For relative imports you have to:

• a) use relative name

• b) provide anchor explicitly

  importlib.import_module('.c', 'a.b') 

Of course, you could also just do absolute import instead:

importlib.import_module('a.b.c') 

Answer 2

I think it's better to use importlib.import_module('.c', __name__) since you don't need to know about a and b.

I'm also wondering that, if you have to use importlib.import_module('a.b.c'), why not just use import a.b.c?