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

Work with libraries. Make a library called nib, install it using setup.py, let it reside in site-packages and your problems are solved. You don't have to stuff everything you make in a single package. Break it up to pieces.

Answer 2

In a Linux system, you can create a soft link from the "life" folder to the nib.py file. Then, you can simply import it like:

import nib

Answer 3

import sys sys.path.append('../')

Answer 4

If adding your module folder to the PYTHONPATH didn't work, You can modify the sys.path list in your program where the Python interpreter searches for the modules to import, the python documentation says:

When a module named spam is imported, the interpreter first searches for a built-in module with that name. If not found, it then searches for a file named spam.py in a list of directories given by the variable sys.path. sys.path is initialized from these locations:

• the directory containing the input script (or the current directory).
• PYTHONPATH (a list of directory names, with the same syntax as the shell variable PATH).
• the installation-dependent default.

After initialization, Python programs can modify sys.path. The directory containing the script being run is placed at the beginning of the search path, ahead of the standard library path. This means that scripts in that directory will be loaded instead of modules of the same name in the library directory. This is an error unless the replacement is intended.

Knowing this, you can do the following in your program:

import sys
# Add the ptdraft folder path to the sys.path list
sys.path.append('/path/to/ptdraft/')

# Now you can import your module
from ptdraft import nib
# Or just
import ptdraft

Answer 5

same sort of style as the past answer - but in fewer lines :P

import os,sys
parentdir = os.path.dirname(__file__)
sys.path.insert(0,parentdir)

file returns the location you are working in

Answer 6

The pathlib library (included with >= Python 3.4) makes it very concise and intuitive to append the path of the parent directory to the PYTHONPATH:

import sys
from pathlib import Path
sys.path.append(str(Path('.').absolute().parent))