Importing from a relative path in Python
PythonPython 3.xImportShared LibrariesRelative PathPython Problem Overview
I have a folder for my client code, a folder for my server code, and a folder for code that is shared between them
Proj/
Client/
Client.py
Server/
Server.py
Common/
__init__.py
Common.py
How do I import Common.py from Server.py and Client.py?
Python Solutions
Solution 1 - Python
EDIT Nov 2014 (3 years later):
Python 2.6 and 3.x supports proper relative imports, where you can avoid doing anything hacky. With this method, you know you are getting a relative import rather than an absolute import. The '..' means, go to the directory above me:
from ..Common import Common
As a caveat, this will only work if you run your python as a module, from outside of the package. For example:
python -m Proj
Original hacky way
> This method is still commonly used in some situations, where you aren't actually ever 'installing' your package. For example, it's popular with Django users.
You can add Common/ to your sys.path (the list of paths python looks at to import things):
import sys, os
sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'Common'))
import Common
os.path.dirname(__file__)
just gives you the directory that your current python file is in, and then we navigate to 'Common/' the directory and import 'Common' the module.
Solution 2 - Python
Don't do relative import.
From PEP8:
> Relative imports for intra-package imports are highly discouraged.
Put all your code into one super package (i.e. "myapp") and use subpackages for client, server and common code.
Update: "Python 2.6 and 3.x supports proper relative imports (...)". See Dave's answers for more details.
Solution 3 - Python
Funny enough, a same problem I just met, and I get this work in following way:
combining with linux command ln
, we can make thing a lot simper:
1. cd Proj/Client
2. ln -s ../Common ./
3. cd Proj/Server
4. ln -s ../Common ./
And, now if you want to import some_stuff
from file: Proj/Common/Common.py
into your file: Proj/Client/Client.py
, just like this:
# in Proj/Client/Client.py
from Common.Common import some_stuff
And, the same applies to Proj/Server
, Also works for setup.py
process,
a same question discussed here, hope it helps !
Solution 4 - Python
Doing a relative import is absolulutely OK! Here's what little 'ol me does:
#first change the cwd to the script path
scriptPath = os.path.realpath(os.path.dirname(sys.argv[0]))
os.chdir(scriptPath)
#append the relative location you want to import from
sys.path.append("../common")
#import your module stored in '../common'
import common.py
Solution 5 - Python
The default import method is already "relative", from the PYTHONPATH. The PYTHONPATH is by default, to some system libraries along with the folder of the original source file. If you run with -m to run a module, the current directory gets added to the PYTHONPATH. So if the entry point of your program is inside of Proj, then using import Common.Common
should work inside both Server.py and Client.py.
Don't do a relative import. It won't work how you want it to.
Solution 6 - Python
Approch used by me is similar to Gary Beardsley mentioned above with small change.
Filename: Server.py
import os, sys
script_path = os.path.realpath(os.path.dirname(__name__))
os.chdir(script_path)
sys.path.append("..")
# above mentioned steps will make 1 level up module available for import
# here Client, Server and Common all 3 can be imported.
# below mentioned import will be relative to root project
from Common import Common
from Client import Client