Permanent Python Path

WildDrake! · 03-15-2016, 06:00 PM

Linux Mint - Cinnamon
python 2.7.6 and Python 3.4.3
bash

I know this is basic...but...I am trying to get my python path set up so that I can import modules from directories other than the directory I am currently setting within.

I have set my my .bashrc file to include the following incantation:

export PYTHONPATH="${PYTHONPATH}:~/1_Scripts/python:~/1a_Computer_Related/Python/Practice:~/1a_Computer_Related/Python/code:~/1a_Computer_Related/Python/scripts:~/1a_Computer_Related/Python/Applied_Examples:~/python_work"

(My computer has been rebooted many times while trying to get this to work, so surely .bashrc is as read as it is ever going to get by the OS.)

However, so far I haven't gotten the interactive immediate mode of python (the console command line) to import anything from any of these directories. I have tried different incantations I googled, but to no avail...

pets.py is located in the last directory of the above path at ~/python_work :

>>> import pets
or
>>> from pets import Dog

Traceback (most recent call last):
File "<console>", line 1, in <module>
ImportError: No module named pets

What am I doing wrong??? Thanks for your thoughts!

norobro · 03-15-2016, 07:12 PM

At your python prompt type the following and see if you can spot the problem:

Code:

>>> import sys
>>> print(sys.path)

WildDrake! · 03-15-2016, 10:45 PM

Apparently none of the paths for directories where I have placed python programs has been added to the actual path by the before mentioned statement! Below is the result I obtained with the sys.path command:

>>> import sys
>>> print(sys.path)
['', '/home/justme', '/usr/bin', '/usr/lib/python3.4', '/usr/lib/python3.4/plat-x86_64-linux-gnu', '/usr/lib/python3.4/lib-dynload', '/usr/local/lib/python3.4/dist-packages', '/usr/lib/python3/dist-packages']
>>>

So evidently none of the incantations I have found and tried so far are the correct statements....or .bashrc isn't where it wants me to say such things....like I have my Linux Path in the following text file /etc/environment instead of in .bashrc

norobro · 03-16-2016, 10:36 AM

Dunno. Works fine here.

Quote:

Originally Posted by WildDrake!

export
PYTHONPATH="${PYTHONPATH}:~/1_Scripts/python: ...

Probably a copy/paste issue, but are those separate lines in your .bashrc? They need to be on the same line or you need a backslash behind export.

Code:

export \
PYTHONPATH="${PYTHONPATH}:~/1_Scripts/python: ...

Once you get that working you're going to have problems using relative paths though.

WildDrake! · 03-16-2016, 03:37 PM

Hey! We are getting there! (If you haven't guessed...I am working at learning python.)

That seems to have been the problem...kind of. I changed the python relative paths to absolute paths in the .bashrc file, rebooted, and asked python:

Code:

>>> import sys
>>> print(sys.path)
['', '/home/justme', '/home/justme/1_Scripts/python', '/home/justme/1a_Computer_Related/Python/Practice', '/home/justme/1a_Computer_Related/Python/code', '/home/justme/1a_Computer_Related/Python/scripts', '/home/justme/1a_Computer_Related/Python/Applied_Examples', '/home/justme/python_work', '/usr/lib/python3.4', '/usr/lib/python3.4/plat-x86_64-linux-gnu', '/usr/lib/python3.4/lib-dynload', '/usr/local/lib/python3.4/dist-packages', '/usr/lib/python3/dist-packages']
>>>

So, the correct paths are now showing up as being active there.

Now, using the Linux Terminal in Python3 command mode to import from pets.py:

Code:

>>> 
>>> from pets import Pet, Dog
>>> polly = Pet("Polly", "Parrot")
>>> print(polly)
Polly is a Parrot
>>>

Hooray! It works!!!

But if I use the new Ninja python editor which I am trying to learn how to use to do this same thing it's python3 interactive window gives me:

Code:

>>> from pets import Pet, Dog
Traceback (most recent call last):
  File "<console>", line 1, in <module>
ImportError: No module named pets
>>>

Moving over to the Python3 Idle interactive shell for beginners I get the same error:

Code:

>>> from pets import Pet, Dog
Traceback (most recent call last):
  File "<pyshell#1>", line 1, in <module>
    from pets import Pet, Dog
ImportError: No module named 'pets'
>>>

The geany editor in python immediate mode also gives the same "No module named 'pets'" error.

Any suggestions or ideas of why these editor's python immediate mode windows aren't working correctly now?

WildDrake! · 03-16-2016, 03:56 PM

Just realized I hadn't check sys.path from any of the prior mentioned editors.

They do not show any of my personal directories on their sys.path printouts like the standard linux terminal running the python shell did...

WildDrake! · 03-16-2016, 04:12 PM

If I launch Ninja using the desktop launcher, I get the described not found problem. HOWEVER, if I launch Ninja-IDE from the linux command line, the Ninja editor then has the entire python path info and imports work from it's python commandline.

I assume that is what needs to also happen to get the other editors I mentioned to perform correctly also.