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Import a module from a relative path


Question

How do I import a Python module given its relative path?

For example, if dirFoo contains Foo.py and dirBar, and dirBar contains Bar.py, how do I import Bar.py into Foo.py?

Here's a visual representation:

dirFoo\
    Foo.py
    dirBar\
        Bar.py

Foo wishes to include Bar, but restructuring the folder hierarchy is not an option.

2017/08/28
1
762
8/28/2017 1:52:42 PM

Accepted Answer

Assuming that both your directories are real Python packages (do have the __init__.py file inside them), here is a safe solution for inclusion of modules relatively to the location of the script.

I assume that you want to do this, because you need to include a set of modules with your script. I use this in production in several products and works in many special scenarios like: scripts called from another directory or executed with python execute instead of opening a new interpreter.

 import os, sys, inspect
 # realpath() will make your script run, even if you symlink it :)
 cmd_folder = os.path.realpath(os.path.abspath(os.path.split(inspect.getfile( inspect.currentframe() ))[0]))
 if cmd_folder not in sys.path:
     sys.path.insert(0, cmd_folder)

 # Use this if you want to include modules from a subfolder
 cmd_subfolder = os.path.realpath(os.path.abspath(os.path.join(os.path.split(inspect.getfile( inspect.currentframe() ))[0],"subfolder")))
 if cmd_subfolder not in sys.path:
     sys.path.insert(0, cmd_subfolder)

 # Info:
 # cmd_folder = os.path.dirname(os.path.abspath(__file__)) # DO NOT USE __file__ !!!
 # __file__ fails if the script is called in different ways on Windows.
 # __file__ fails if someone does os.chdir() before.
 # sys.argv[0] also fails, because it doesn't not always contains the path.

As a bonus, this approach does let you force Python to use your module instead of the ones installed on the system.

Warning! I don't really know what is happening when current module is inside an egg file. It probably fails too.

2017/08/28
335
8/28/2017 1:55:41 PM

Be sure that dirBar has the __init__.py file -- this makes a directory into a Python package.

2008/11/10

You could also add the subdirectory to your Python path so that it imports as a normal script.

import sys
sys.path.insert(0, <path to dirFoo>)
import Bar
2018/02/07

import os
import sys
lib_path = os.path.abspath(os.path.join(__file__, '..', '..', '..', 'lib'))
sys.path.append(lib_path)

import mymodule
2018/01/26

Just do simple things to import the .py file from a different folder.

Let's say you have a directory like:

lib/abc.py

Then just keep an empty file in lib folder as named

__init__.py

And then use

from lib.abc import <Your Module name>

Keep the __init__.py file in every folder of the hierarchy of the import module.

2017/08/28

If you structure your project this way:

src\
  __init__.py
  main.py
  dirFoo\
    __init__.py
    Foo.py
  dirBar\
    __init__.py
    Bar.py

Then from Foo.py you should be able to do:

import dirFoo.Foo

Or:

from dirFoo.Foo import FooObject

Per Tom's comment, this does require that the src folder is accessible either via site_packages or your search path. Also, as he mentions, __init__.py is implicitly imported when you first import a module in that package/directory. Typically __init__.py is simply an empty file.

2017/08/28