Permanently add a directory to PYTHONPATH?

Question

Whenever I use sys.path.append, the new directory will be added. However, once I close python, the list will revert to the previous (default?) values. How do I

Answer 1

The add a new path to PYTHONPATH is doing in manually by:

adding the path to your ~/.bashrc profile, in terminal by:

vim ~/.bashrc

paste the following to your profile

export PYTHONPATH="${PYTHONPATH}:/User/johndoe/pythonModule"

then, make sure to source your bashrc profile when ever you run your code in terminal:

source ~/.bashrc 

Hope this helps.

Answer 2

For me it worked when I changed the .bash_profile file. Just changing .bashrc file worked only till I restarted the shell.

For python 2.7 it should look like:

export PYTHONPATH="$PYTHONPATH:/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python"

at the end of the .bash_profile file.

Answer 3

I added permanently in Windows Vista, Python 3.5

System > Control Panel > Advanced system settings > Advanced (tap) Environment Variables > System variables > (if you don't see PYTHONPATH in Variable column) (click) New > Variable name: PYTHONPATH > Variable value:

Please, write the directory in the Variable value. It is details of Blue Peppers' answer.

Answer 4

In case anyone is still confused - if you are on a Mac, do the following:

1. Open up Terminal
2. Type open .bash_profile
3. In the text file that pops up, add this line at the end: export PYTHONPATH=$PYTHONPATH:foo/bar
4. Save the file, restart the Terminal, and you're done

Answer 5

On linux you can create a symbolic link from your package to a directory of the PYTHONPATH without having to deal with the environment variables. Something like:

ln -s /your/path /usr/lib/pymodules/python2.7/

Answer 6

Instead of manipulating PYTHONPATH you can also create a path configuration file. First find out in which directory Python searches for this information:

python -m site --user-site

For some reason this doesn't seem to work in Python 2.7. There you can use:

python -c 'import site; site._script()' --user-site

Then create a .pth file in that directory containing the path you want to add (create the directory if it doesn't exist).

For example:

# find directory
SITEDIR=$(python -m site --user-site)

# create if it doesn't exist
mkdir -p "$SITEDIR"

# create new .pth file with our path
echo "$HOME/foo/bar" > "$SITEDIR/somelib.pth"