Importing modules from parent folder

Question

I am running Python 2.5.

This is my folder tree:

ptdraft/
  nib.py
  simulations/
    life/
      life.py

(I also have __init

Answer 1

You could use relative imports (python >= 2.5):

from ... import nib

(What’s New in Python 2.5) PEP 328: Absolute and Relative Imports

EDIT: added another dot '.' to go up two packages

Answer 2

Relative imports (as in from .. import mymodule) only work in a package. To import 'mymodule' that is in the parent directory of your current module:

import os,sys,inspect
currentdir = os.path.dirname(os.path.abspath(inspect.getfile(inspect.currentframe())))
parentdir = os.path.dirname(currentdir)
sys.path.insert(0,parentdir) 

import mymodule

edit: the __file__ attribute is not always given. Instead of using os.path.abspath(__file__) I now suggested using the inspect module to retrieve the filename (and path) of the current file

Answer 3

Although it is against all rules, I still want to mention this possibility:

You can first copy the file from the parent directory to the child directory. Next import it and subsequently remove the copied file:

for example in life.py:

import os
import shutil

shutil.copy('../nib.py', '.')
import nib
os.remove('nib.py')

# now you can use it just fine:
nib.foo()

Of course there might arise several problems when nibs tries to import/read other files with relative imports/paths.

Answer 4

I made this library to do this.

https://github.com/fx-kirin/add_parent_path

# Just add parent path
add_parent_path(1)

# Append to syspath and delete when the exist of with statement.
with add_parent_path(1):
   # Import modules in the parent path
   pass