Python: import the containing package

Question

In a module residing inside a package, i have the need to use a function defined within the __init__.py of that package. how can i import the package within the module that resides within the package, so i can use that function?

Importing __init__ inside the module will not import the package, but instead a module named __init__, leading to two copies of things with different names...

Is there a pythonic way to do this?

Sandoval

Answer 1

Also, starting in Python 2.5, relative imports are possible. e.g.:

from . import foo

Quoting from http://docs.python.org/tutorial/modules.html#intra-package-references:

---

Starting with Python 2.5, in addition to the implicit relative imports described above, you can write explicit relative imports with the from module import name form of import statement. These explicit relative imports use leading dots to indicate the current and parent packages involved in the relative import. From the surrounding module for example, you might use:

from . import echo
from .. import formats
from ..filters import equalizer

Liberal

This does not answer the question of how to import from __init__.py. – Moffat

@BrenBarn: yet this is the way to import it; when you import the package, the __init__.py file serves as the effective namespace. You should never import __init__.py directly. – Guffaw

Answer 2

This doesn't exactly answer your question, but I'm going to suggest that you move the function outside of the __init__.py file, and into another module inside that package. You can then easily import that function into your other module. If you want, you can have an import statement in the __init__.py file that will import that function (when the package is imported) as well.

Beforetime

i realise i can do this, it just seems rather messy and um, unpythonic. – Sandoval

Not sure how this is 'unpythonic'? Wouldn't the alternative be even more messy, since init.py is not really a module? – Minnesota

+1 - using a common.py within your package is very usual practice in Python. – Swain

I've been messing around and haven't found any better way – Kroeger

Answer 3

If the package is named testmod and your init file is therefore testmod/__init__.py and your module within the package is submod.py then from within submod.py file, you should just be able to say import testmod and use whatever you want that's defined in testmod.

Chancelor

Answer 4

I'm not totally sure what the situation is, but this may solve your "different name" problem:

import __init__ as top
top.some_function()

Or maybe?:

from __init__ import some_function
some_function()

Swain

This does work, but at least in cPython 2.7 the interpreter considers __init__ to be a different module than top, and so the __init__.py file gets loaded twice. – Hadji

This is an implicit relative import, and as such won't work in python 3, and is bad practice in python 2 anyway. – Tbilisi

This still creates sys.modules['__init__']. Basically, the __init__.py module should never be directly imported. Import the package (the directory name) instead. – Guffaw

Answer 5

In Django, the file manage.py has from django.core.management import execute_manager, but execute_manager is not a module. It is a function within the __init__.py module of the management directory.

Plaice