What exactly should be set in PYTHONPATH

Question

I m going through and writing a setup doc for other developers at work for a python project and I ve been reading up on the PYTHONPATH environment variable  I m looking at my current development system and think I have a few things set wrong that is causing my IDE  IntelliJ  to behave incorrectly when looking up the python libraries   I ve looked at the documentation here and here and I m still unsure of what should actually be in the PYTHONPATH environment variable    I have PYTHONHOME pointed to  C  Python27    My current PYTHONPATH is set to PYTHONHOME  Should I also add the directories from sys path   UPDATE   Based on the below information  PYTHONPATH does not need to be set unless there are non-standard libraries that you want python to be able to find by default  For instance  when I install wxPython from the installer it will add its libraries to PYTHONPATH  I do set PYTHONHOME to the root of the python installation so that I can add it to my system PATH environment variable so that I can run python from any where

User · Answer

For most installations  you should not set these variables since they are not needed for Python to run   Python knows where to find its standard library   The only reason to set PYTHONPATH is to maintain directories of custom Python libraries that you do not want to install in the global default location  i e   the site-packages directory    Make sure to read  http   docs python org using cmdline html environment-variables

User · Answer

Here is what I learned  PYTHONPATH is a directory to add to the Python import search path  sys path   which is made up of current dir  CWD  PYTHONPATH  standard and shared library  and customer library  For example      python3 -c  import sys print sys path           home username Documents DjangoTutorial mySite      usr lib python3 6     usr lib python3 6 lib-dynload      usr local lib python3 6 dist-packages     usr lib python3 dist-packages     where the first path    denotes the current dir   the 2nd path is via    export PYTHONPATH  home username Documents DjangoTutorial mySite    which can be added to    bashrc to make it permanent  and the rest are Python standard and dynamic shared library plus third-party library such as django     As said not to mess with PYTHONHOME  even setting it to    or  None  will cause python3 shell to stop working     export PYTHONHOME      python3 Fatal Python error  Py Initialize  Unable to get the locale encoding ModuleNotFoundError  No module named  encodings   Current thread 0x00007f18a44ff740  most recent call first   Aborted  core dumped    Note that if you start a Python script  the CWD will be the script s directory  For example   username bud   Documents DjangoTutorial  python3 mySite manage py runserver      Printing sys path       home username Documents DjangoTutorial mySite   CWD is where manage py resides  usr lib python3 6  usr lib python3 6 lib-dynload  usr local lib python3 6 dist-packages  usr lib python3 dist-packages   You can also append a path to sys path at run-time  Suppose you have a file Fibonacci py in   Documents Python directory   username bud   Documents DjangoTutorial  python3   gt  gt  gt  sys path append   home username Documents    gt  gt  gt  print sys path         usr lib python3 6     usr lib python3 6 lib-dynload      usr local lib python3 6 dist-packages     usr lib python3 dist-packages      home username Documents    gt  gt  gt  from Python import Fibonacci as fibo   or via    PYTHONPATH  home username Documents  PYTHONPATH   python3  gt  gt  gt  print sys path          home username Documents     home username Documents DjangoTutorial mySite      usr lib python3 6     usr lib python3 6 lib-dynload      usr local lib python3 6 dist-packages     usr lib python3 dist-packages    gt  gt  gt  from Python import Fibonacci as fibo

User · Answer

You don t have to set either of them   PYTHONPATH can be set to point to additional directories with private libraries in them   If PYTHONHOME is not set  Python defaults to using the directory where python exe was found  so that dir should be in PATH

[python] What exactly should be set in PYTHONPATH?

Examples related to python