python error: "ImportError: No module named encodings"

Question

I'm in a bit of a python death spiral, here, with the "ImportError: No module named encodings" error when I try using python. I've read a dozen or so different posts on the problem, and none of them help. Advice welcome (please be specific, since I'm a bit of a novice).

The original install was done as part of an OpenCV installation here. I was able to use the virtual environment and do everything I needed to do. Then this morning I picked up the RPi again and did an update/upgrade. Now, when I log on (or source .profile), I get:

pi@raspberrypi:~ $ source .profile
Could not find platform independent libraries <prefix>
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Fatal Python error: Py_Initialize: Unable to get the locale encoding
ImportError: No module named 'encodings'

Current thread 0x76f06010 (most recent call first):
virtualenvwrapper.sh: There was a problem running the initialization hooks.

If Python could not import the module virtualenvwrapper.hook_loader,
check that virtualenvwrapper has been installed for
VIRTUALENVWRAPPER_PYTHON=/usr/bin/python3 and that PATH is
set properly.

I can run python2.7, but attempting to import locale give a similar error:

pi@raspberrypi:~ $ python
Python 2.7.13 (default, Nov 24 2017, 17:33:09) 
[GCC 6.3.0 20170516] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import locale
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.7/locale.py", line 13, in <module>
    import encodings
ImportError: No module named encodings
>>> 

python3 won't run at all:

pi@raspberrypi:~ $ python3
Could not find platform independent libraries <prefix>
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Fatal Python error: Py_Initialize: Unable to get the locale encoding
ImportError: No module named 'encodings'

Current thread 0x76f91010 (most recent call first):
Aborted

Some threads suggest setting $PYTHONHOME and $PYTHONPATH; others say not to (that's the point of the virtual environment). I've tried setting them -- though I'm not 100% sure of what to set them to -- but the outputs above are with them unset. I have set:

VIRTUALENVWRAPPER_PYTHON=/usr/bin/python3

and the path is:

pi@raspberrypi:~ $ echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/games:/usr/games

This thread suggests rebuilding the virtual environment, but that just gives me the same errors:

pi@raspberrypi:~ $ rm -rf venv
pi@raspberrypi:~ $ virtualenv -p /use/bin/python3/ venv/
Could not find platform independent libraries <prefix>
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Fatal Python error: Py_Initialize: Unable to get the locale encoding
ImportError: No module named 'encodings'

Current thread 0x76fd3010 (most recent call first):
Aborted

Suggestions for what to try next? I'm hoping it's just an env setting that I've screwed up, but I can't figure it out.

It took a long time to get OpenCV up and running -- I'd hate to have to redo all of that.

Answer 1

It sounds like your install process was a bit complicated, so perhaps the first thing is to get some knowledge of what you have in your modules collection. Examine what you have in your python*/site-packages directories - these will be found in /usr/lib, /usr/lib64, and possibly /usr/local/lib and or lib64. encodings might be there, but the OS or python might need a crutch to be able to find it, with a file soft link "ln -s ..." for example.