python not importing from current directory

Question

I'm using python 2.7 in a linux environment and I'm having trouble importing a .py file under certain conditions. My directory-tree is as follows:

/mainFolder
    executable.py
    /Folder
         input_file.py

executable.py imports input_file.py with the line __import__('input_file')

When I am in the folder mainFolder/Folder and I run ../executable.py I get the output: ImportError: No module named input_file

And when I move input_file.py into mainFolder it works. From looking at it I'm under the impression that input_file.py isn't in python's path and I know how to fix that.

I'm under the impression though that it should work as is, as this is code that is from a github repository and presumably works on the author's computer, but this is apparently not the case.

Is there a setting I can change so I don't have to do something like sys.path.append(0,'mainFolder/Folder')?

Why are you using the import function `__import__()` instead of the plain `import` keyword? — John Gordon, Dec 07 '16 at 18:36
I'm using the `__import__()` because I'm actually passing `executable.py` the input file as an input which it imports that way, I don't want to have to alter `executable.py` every time I use a new input file. — James Urban, Dec 07 '16 at 18:51

score 3 · Answer 1 · edited May 23 '17 at 10:30

"Packages" in python are identified by a file called

__init__.py

in the root of this package folder.

In this case, your tree should appears like:

/mainFolder
    executable.py
    /Folder
         **__init__.py**
         input_file.py

In this case, if you want import module: input_file as a module, you can declare in executable:

from Folder import input_file

or even

from Folder.input_file import *
from Folder import *

As alternative and following explanation found in this response, I implemented an example for your directory structure:

executable.py file content:

Folder = __import__('Folder.input_file')
print(Folder.input_file.summm(1,2))

input_file.py file content:

def summm(a, b):
    return a+b

It is ugly, but was the to build an example following your original structure. In this case, it is not ncessary to add __init__.py file inside Folder folder.

I've thought about this too, but there aren't any __init__.py files in the github repository, and shouldn't python recognize packages that are in the directory you are in on your operating system? — James Urban, Dec 07 '16 at 18:57
James, I edited the post for the structure you described. It works in your case? — Andre Pastore, Dec 13 '16 at 01:56

score 0 · Answer 2 · edited Dec 07 '16 at 18:40

0

You can easily fix it

import Folder.input_file

or

__import__('Folder.input_file')

Where Folder is the name of the folder input_file.py is in.

edited Dec 07 '16 at 18:40

Andrea Corbellini

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answered Dec 07 '16 at 18:37

Patrick Abraham

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Is this a quirk of Python 2.7, since it works flawless with Python 3.5.2 – Patrick Abraham Dec 07 '16 at 18:39
You might need an `__init__.py` in `Folder` for that to work. It can be empty. – Mad Physicist Dec 07 '16 at 18:43
At least with 3.5.2 you don't. Andrea said the same thing – Patrick Abraham Dec 07 '16 at 18:44

python not importing from current directory

2 Answers2