Add to python path mac os x

I thought

import sys sys.path.append("/home/me/mydir") 

is appending a dir to my pythonpath

if I print sys.path my dir is in there.

Then I open a new command and it is not there anymore.

But somehow Python cant import modules I saved in that dir.

What Am I doing wrong?

I read .profile or .bash_profile will do the trick.

Do I have to add:

PATH="/Me//Documents/mydir:$PYTHONPATH" export PATH 

To make it work?

7 Answers

Modifications to sys.path only apply for the life of that Python interpreter. If you want to do it permanently you need to modify the PYTHONPATH environment variable:

PYTHONPATH="/Me/Documents/mydir:$PYTHONPATH" export PYTHONPATH 

Note that PATH is the system path for executables, which is completely separate.

**You can write the above in ~/.bash_profile and the source it using source ~/.bash_profile

Not sure why Matthew's solution didn't work for me (could be that I'm using OSX10.8 or perhaps something to do with macports). But I added the following to the end of the file at ~/.profile

export PYTHONPATH=/path/to/dir:$PYTHONPATH 

my directory is now on the pythonpath -

my-macbook:~ aidan$ python Python 2.7.2 (default, Jun 20 2012, 16:23:33) [GCC 4.2.1 Compatible Apple Clang 4.0 (tags/Apple/clang-418.0.60)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> import sys >>> sys.path ['', '/path/to/dir', ... 

and I can import modules from that directory.

On MAC OS you can simply find the location of python/python3 by using the command which python or which python3. (works for Linux too)

And it should give something like:

For python

/usr/local/bin/python 

For python3

/Library/Frameworks/ 

Export the path to your bash_profile

In your terminal type

sudo nano ~/.bash_profile 

Enter your password and paste the following lines

PYTHONPATH="/Library/Frameworks/" export PYTHONPATH 

Press control + x to exit, and press y for saving on being asked to save

Press `enter' to return to terminal window

Source it using the following command in terminal, run

source ~/.bash_profile 

Path to python3 should be updated now!!

Mathew's answer works for the terminal python shell, but it didn't work for IDLE shell in my case because many versions of python existed before I replaced them all with Python2.7.7. How I solved the problem with IDLE.

1. In terminal, cd /Applications/Python\ 2.7/
2. then sudo nano idlemain.py, enter password if required.
3. after os.chdir(os.path.expanduser('~/Documents')) this line, I added sys.path.append("/Users/admin/Downloads....") NOTE: replace contents of the quotes with the directory where python module to be added
4. to save the change, ctrl+x and enter Now open idle and try to import the python module, no error for me!!!

Setting the $PYTHONPATH environment variable does not seem to affect the Spyder IDE's iPython terminals on a Mac. However, Spyder's application menu contains a "PYTHONPATH manager." Adding my path here solved my problem. The "PYTHONPATH manager" is also persistent across application restarts.

This is specific to a Mac, because setting the PYTHONPATH environment variable on my Windows PC gives the expected behavior (modules are found) without using the PYTHONPATH manager in Spyder.

On MacOS Big Surf the file to add the "export" is $HOME/.zprofile

So, this should work for adding PYTHONPATH to your Mac Big Surf environment variables:

export PYTHONPATH=$HOME/my_folder 

If the file doesn't exist just create it in $HOME, normally /Users/my_user_name

This change in the file name is because the default shell for MacOS Big Surf is zsh and not bash

In my .zshrc file located at /Users/your_username/.zshrc

I add the following line: export PYTHONPATH="${PYTHONPATH}:/your/path" and save it.

If the file doesn't exist, create a nameless .txt file and change its extension to .zshrc. It's a hidden file, so you need to press cmd+shift+. to see it.

I am using macOS Monterey.