How to put a Python module in a different folder than my script?

Question

I’m trying to run a Python script (v2.4 and v2.7) and created a module with some methods. Unfortunately this module needs to stay in a separate folder.

In the python documentation and so far on Stack Overflow I found numerous post talking to add the __init__.py in every folder of my project.

My problem is that my script is in one structure and my module is in another. My situation is this:

pasta1/
   script.py
pasta2/
   modules/
      python/
          pasta3/
              \__init\__.py
               modulo1.py
               modulo2.py

The part I’m calling these modules in my script is:

#!/usr/bin/python

# -*- coding: utf-8 -*-

import sys  
import datetime  

from pasta3.modulo1 import Mod1  
from pasta3.modulo2 import Mod2 

The mistake:

$ ./script.py   
Traceback (most recent call last):  
     File "./script.py", line 9, in <module> from pasta3.modulo1 import Mod1  
ImportError: No module named pasta3.modulo1

I can’t use the sys.path.append("../modules/python/") because in the Python 2.4 he is not recognized.

How to proceed in this case?

Answer 1

Try to return a directory and indicate the path.

Example:

script py.

from ..pasta3.modulo1 import Mod1

Answer 2

In Python 2.x, you can use the module Imp:

This module provides an interface to the mechanisms used to implement the import statement.

Use the functions find_module and load_module.

• find_module: Will search the module by name, if the search is successful, the return value is a tuple of 3 elements containing the file, path, and description.

• load_module: Will import the module, if the module has already been imported, it will only be reloaded - equivalent to function reload. The return is an object that points to the module, otherwise an exception ImportError is launched.

Example:

import imp

arquivo, caminho, descricao = imp.find_module('Modulo1', ['/foo/bar/baz/'])

modulo1 = imp.load_module('Modulo1', arquivo, caminho, descricao)

modulo1.funcao1()

---

From the version +3.4 python the module Imp became obsolete, as an alternative you can use the module importlib (is available from Python 2.7).

Answer 3

Configure the environment variable PYTHONPATH and include (append if it already exists) the directory pasta3:

export PYTHONPATH = /pasta2/modules/python/pasta3

In any case, you can use the full path to pasta3 instead of relative.

Answer 4

Why not use a symlink for pasta2 within the pasta1:

$ ln -s ./pasta2 ./pasta1/pasta2