How do you set your pythonpath in an already-created virtualenv?

What file do I edit, and how? I created a virtual environment.

The most elegant solution to this problem is here.

Original answer remains, but this is a messy solution:

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If you want to change the PYTHONPATH used in a virtualenv, you can add the following line to your virtualenv's bin/activate file:

export PYTHONPATH="/the/path/you/want"

This way, the new PYTHONPATH will be set each time you use this virtualenv.

EDIT: (to answer @RamRachum's comment)

To have it restored to its original value on deactivate, you could add

export OLD_PYTHONPATH="$PYTHONPATH"

before the previously mentioned line, and add the following line to your bin/postdeactivate script.

export PYTHONPATH="$OLD_PYTHONPATH"

The comment by @s29 should be an answer:

One way to add a directory to the virtual environment is to install virtualenvwrapper (which is useful for many things) and then do

mkvirtualenv myenv
workon myenv
add2virtualenv . #for current directory
add2virtualenv ~/my/path

If you want to remove these path edit the file myenvhomedir/lib/python2.7/site-packages/_virtualenv_path_extensions.pth

Documentation on virtualenvwrapper can be found at http://virtualenvwrapper.readthedocs.org/en/latest/

Specific documentation on this feature can be found at http://virtualenvwrapper.readthedocs.org/en/latest/command_ref.html?highlight=add2virtualenv

You can create a .pth file that contains the directory to search for, and place it in the {venv-root}/lib/{python-version}/site-packages directory. E.g.:

cd $(python -c "from distutils.sysconfig import get_python_lib; print(get_python_lib())")
echo /some/library/path > some-library.pth

The effect is the same as adding /some/library/path to sys.path, and remain local to the virtualenv setup.

1. Initialize your virtualenv

cd venv

source bin/activate

2. Just set or change your python path by entering command following:

export PYTHONPATH='/home/django/srmvenv/lib/python3.4'

3. for checking python path enter in python:

   python

      \>\> import sys
   
      \>\> sys.path

I modified my activate script to source the file .virtualenvrc, if it exists in the current directory, and to save/restore PYTHONPATH on activate/deactivate.

You can find the patched activate script here.. It's a drop-in replacement for the activate script created by virtualenv 1.11.6.

Then I added something like this to my .virtualenvrc:

export PYTHONPATH="${PYTHONPATH:+$PYTHONPATH:}/some/library/path"

It's already answered here -> https://stackoverflow.com/questions/4686463/is-my-virtual-environment-python-causing-my-pythonpath-to-break

UNIX/LINUX

Add "export PYTHONPATH=/usr/local/lib/python2.0" this to ~/.bashrc file and source it by typing "source ~/.bashrc" OR ". ~/.bashrc".

WINDOWS XP

1. Go to the Control panel
2. Double click System
3. Go to the Advanced tab
4. Click on Environment Variables

In the System Variables window, check if you have a variable named PYTHONPATH. If you have one already, check that it points to the right directories. If you don't have one already, click the New button and create it.

PYTHON CODE

Alternatively, you can also do below your code:-

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