How to fix the python path

Question

I have python 2.7.2 installed on my Mac. I installed using python-2.7.2-macosx10.6.dmg I have only one instance of python.

When i type in the terminal to find the python path , I get this :

 python
Python 2.7.2 (v2.7.2:8527427914a2, Jun 11 2011, 15:22:34) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import os.path
>>> os.environ['PYTHONPATH'].split(os.pathsep)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/UserDict.py", line 23, in __getitem__
    raise KeyError(key)
KeyError: 'PYTHONPATH'

It is the one thing missing so I can install Mercurial. I was using Mercurial before and I may have broken something. Do you know how to fix this problem ?

Are you sure you want the contents of the environment variable `PYTHONPATH` specifically, or do you just want to know where Python looks for packages? — David Z, Feb 16 '12 at 22:50
I'm not sure to understand your question. I display the contents of the environment variable and it raises a KeyError. How to fix PYTHONPATH ? so set the environment variable in the right place . — Raymond Chenon, Feb 16 '12 at 22:59

score 6 · Accepted Answer · edited Aug 18 '20 at 12:00

6

You need to modify the sys.path array. It is initialized from the Python defaults and the environment variable "PYTHONPATH": http://docs.python.org/library/sys.html#sys.path

To append your directory the active path:

import sys
sys.path.append("/path/to/your/dir")

edited Aug 18 '20 at 12:00

anroesti

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answered Feb 16 '12 at 23:07

Ivan Kolodyazhny

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Thanks Ivan I'll try when I get back home. Can you provide code sample to set the PYTHONPATH ? – Raymond Chenon Feb 17 '12 at 13:08
I've added sample to my response – Ivan Kolodyazhny Feb 17 '12 at 13:59
2

Not sure why @roy-m-j feels that there needs to be a semicolon there, but Python does not require this to indicate a line change. – Lars Jan 20 '14 at 09:58
@Lars some might even consider it un-pythonic to have a semicolon there. I removed it – anroesti Aug 18 '20 at 12:00

score 1 · Answer 2 · answered Sep 23 '17 at 02:03

Here's another useful tip:

Look under your ~/.local folder. There may be a homebrew.pth (or *.pth) file under ~/.local/lib/ which may cause issue by overriding the python path.

If unsetting $PYTHONPATH doesn't fix your issue, try removing the:

~/.local folder.

How to fix the python path

2 Answers2

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