Can I move a virtualenv?

Question

This question is not a duplicate.

It pertains not just to renaming a virtual environment, but to actually moving it to a different directory, including, potentially, a different user's directory.

This is not the same as merely renaming a virtual environment, especially to people unfamiliar with virtualenvs.

If I create a virtualenv, and I move it to a different folder, will it still work?

$ virtualenv -p /usr/bin/python3 /home/me/Env/my-python-venv
$ source Env/my-python-venv/bin/activate
(my-python-venv) $ 

...later that day, the virtual environment MOVED...

(my-python-venv) $ deactivate
$ mkdir -p /home/me/PeskyPartyPEnvs
$ mv /home/me/Env/my-python-venv /home/me/PeskyPartyPEnvs/

Question:

Will this work?

$ source /home/me/PeskyPartyPEnvs/my-python-venv/bin/activate
(my-python-venv) $ /home/me/PeskyPartyPEnvs/my-python-venv/bin/pip3 install foaas

I mean this as less of a question about the wisdom of trying this (unless that wisdom is humorous, of course), and more about whether it's possible. I really want to know whether it's possible to do in Python 3, or whether I just have to suck it up and clone it.

Can I just mv a virtualenv like that without sadness? I do want to avoid sadness.

Answer 1

BUT ALAS:

No, you can't simply mv. There are workarounds, but it might be easier to reinstall.

(my-python-venv)$ /home/me/PeskyPartyPEnvs/pip3 install foaas
zsh: /home/me/PeskyPartyPEnvs/pip3: bad interpreter: /home/me/Env/my-python-venv/bin/python3: no such file or directory
(my-python-venv)$ deactivate
$ 

... presses enter a lot in frustration, and the following works

$
$
$ pip3 search foaas

Except it is not from my-python-venv, ergo sadness.

Want to mv your virtualenv and use it, otherwise unmodified?

Short Answer:

Well, ya can't.

Answer 2

Yes, this should be possible if you haven't done anything that depends on the current directory of the virtualenv.

However, if you have the choice, the best thing to do is to create new virtualenv and start using the new virtualenv instead. This is the safest choice and least likely to cause issues later.

The documentation does mention that:

Each virtualenv has path information hard-coded into it,

For example, if you have run setvirtualenvproject then it won't be able to switch to the right directory after you run workon ... so in that case you'd need to fix that manually.

In general a virtualenv is little more than a directory with the necessary Python interpreter files plus packages that you need.

Answer 3

The --relocatable argument to virtualenv appears to allow you to do this.

Answer 4

Yes. It is possible to move it on the same platform. You can use --relocatable on an existing environment.

From --help:

--relocatable -- Make an EXISTING virtualenv environment relocatable. This fixes up scripts and makes all .pth files relative.

HOWEVER, this does NOT seem to change the activate script, and rather only changes the pip* and easy_install* scripts. In the activate script, the $VIRTUAL_ENV environment variable hardcoded as the original /path/to/original/venv. The $VIRTUAL_ENV variable is used to set the PATH of your active environment too, so it must be changed based on the new location in order to call python and pip etc. without absolute path.

To fix this issue, you can change the $VIRTUAL_ENV environment variable in the activate script (for example using sed), and everything should be good to go.

An example of usage:

$ cd ~/first
$ virtualenv my-venv
$ grep 'VIRTUAL_ENV=' my-venv/bin/activate
VIRTUAL_ENV="/home/username/first/my-venv"
$ virtualenv --relocatable my-venv
Making script my-venv/bin/easy_install relative
Making script my-venv/bin/easy_install-2.7 relative
Making script my-venv/bin/pip relative
Making script my-venv/bin/pip2 relative
Making script my-venv/bin/pip2.7 relative
### Note that `activate` has not been touched
$ mkdir ~/second
$ mv my-venv ~/second
$ cd ~/second
$ grep 'VIRTUAL_ENV=' my-venv/bin/activate
VIRTUAL_ENV=/home/username/first/my-venv
### (This variable hasn't been changed, it still refers to the old, now non-existent directory!)
$ sed -i -e 's|username/first|username/second|' my-venv/bin/activate
## sed can be used to change the path.
## Note that the `-i` (in place) flag won't work on all machines. 
$ source my-venv/bin/activate 
(my-venv) $ pip install foass
...
(my-venv) $ python 
[...]
> import foass

Hooray, now you can install things and load them into your newly located virtual environment.

Answer 5

Using answers of this and other threads about similar topic, I've made a bash script that, located and executed within the virtualenv directory itself, will help with your virtualenv moves.

After doing virtualenv --relocatable yourenv you'll need to change your VIRTUAL_ENV variable every time you move the directory, so if you don't wan't to change it manually, use this.

#!/bin/bash \n 
DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
EXISTING=$(grep 'VIRTUAL_ENV=' bin/activate)  
NEWDIR=VIRTUAL_ENV=\"$DIR\"
sed -i -e "s|$EXISTING|$NEWDIR|" bin/activate
source bin/activate

I hope it helps.

Answer 6

For Python 3.3+ (with new venv built-in module)

Short Answer (regardless of version):

• There's no clean, direct way to move a virtual environment
• Just recreate, it's easy!!

---

Long Answer:

As of Python v3.3, the virtualenv package has become a built-in module named venv.

The --relocatable option mentioned in other answers has not been included in venv, and currently there is no good, safe way that I'm aware of to either rename or relocate a Python virtual environment.

However, it is fairly simple to recreate a virtual environment, with all its currently installed packages. See this answer, or see the section below. During the process you can recreate the new environment in whatever location and with whatever name you desire.

In the answer linked above, he mentions some 3rd party packages which may support direct renames or moves. If you are settled on pursuing a way to move a virtual environment, you could look into if those work with venv as well.

Note: In that answer, it is focused on virtualenv, rather than venv. See next section for how to translate.

---

venv vs. older virtualenv command syntax

The command to use venv is:

python -m venv

rather than just virtualenv, which installs as a command in the original package. Where "python" refers to however you run your python executable, which could be a variety of things, such as:

1. python
2. py or py -3.7 or similar (the Python Launcher for Windows for Python 3.3+ and bundled with Python for Windows, or the py package that can be installed separately for Linux [and MacOS?])
3. python3 (convention for linux environments that dual install python 2 and 3)
4. If you are having issues, use the absolute path to the python executable you want to run: e.g. c:\program files\python37\python.exe

If you are unsure which version is being run, you can always python --version to find out.

---

How to recreate a virtual environment

Creating/recreating a virtual environment is easy and should become second nature after you work with them for a bit. This process mirrors what you would do to distribute your script as a package (with it's dependencies) in the first half, and then what someone would do to install your script/package for further development.

First, get an updated list of what is in the virtual environment. With it active, get the Python version it uses and save out the list of dependencies to a file.

1. Use python --version with the virtual environment activated to see what version of Python it is using.

   • This is for clarity - you may want to update the Python version for various reasons - at least to the latest patch version
   • For example, if the existing venv is using Python v3.7.4, but now v3.7.6 is out - use v3.7.6 instead, which should including only non-breaking security and bug fixes.

2. Use python -m pip freeze > requirements.txt to create the list of current package dependencies and put them into the requirements.txt file. This command works in Linux or the Git Bash for sure - not 100% sure about Powershell or Command Line in Windows.

Now create a new virtual environment and then add the dependencies from the old one.

3. Make your new venv.

   • Make sure you are using the correct version of python that you want to install to the venv.
   • If you want it to be exactly the same Python version:
     • While in the old venv, type "python --version", then make sure you create the new venv with that version of the python command.
   • For the new venv folder entry in the command:
     • Either add an absolute or relative path to the desired final folder location.
     • Use python -m venv my_new_venv to create a new virtual environment in the current working directory in a new my_new_venv folder.
     • The name of the venv folder will be the name of the venv (what shows up in the prompt when it is activated).

4. Install your dependencies from the requirements.txt file.

   • python -m pip install -r requirements.txt

You might need to reinstall local packages that are in development mode.

Note, if you ever need to see the specific location a package is installed to, use:

• python -m pip list -v
• The -v or "verbose" option will add some extra information about each package that is installed, including the path it is installed in. This is useful to make sure you are keeping virtual, user, and system installed packages straight.

At this point you can just delete the old venv folder and all contents. I recommend using a GUI for that - file deletions are often permanent from the linux command line, and a small typo can be bad news.

Answer 7

YES, YOU CAN! (In windows)

The workaround is easy, just move your virtual environment anywhere then edit activate.bat inside scripts\:

1. Move to the virtual environment to the desired directory

2. Right-click and edit activate.bat located at venv_folder\scripts.

3. Change VIRTUAL_ENV variable from:

    set VIRTUAL_ENV=C:\old_directory\venv_name
   

   into

    set VIRTUAL_ENV=C:\new_directory\venv_name
   

4. Save the edited batch file, and thats it!

NOTE: My solution should work and save windows users setting up new virtual environments, I doubt this will work in other operating system since .bat is from MS-DOS

Answer 8

TL;DR

virtualenv-clone is included part of virtualenvwrapper

virtualenv-clone /path/to/old/venv /path/to/new/venv

Alternatively

You could also try cpvirtualenv

cpvirtualenv /path/to/old/venv /path/to/new/venv

But cpvirtualenv expects the /path/to/old/venv to be existing inside $WORKON_HOME and if it isn't it fails. Since this calls virtualenv-clone you may as well use that instead; to avoid errors like

mark@Desktop:~/venvs$ cpvirtualenv ./random/ $WORKON_HOME/random
Copying random as /home/mark/.virtualenvs/venvs/random...
Usage: virtualenv-clone [options] /path/to/existing/venv /path/to/cloned/venv

virtualenv-clone: error: src dir '/home/mark/.virtualenvs/venvs/random' does not exist

Warning as per virtualenvwrapper documentation

Copying virtual environments is not well supported. Each virtualenv has path information hard-coded into it, and there may be cases where the copy code does not know it needs to update a particular file. Use with caution.

What does it actually do ? As per virtualenv-clone PyPi page

A script for cloning a non-relocatable virtualenv.

Virtualenv provides a way to make virtualenv's relocatable which could then be copied as we wanted. However making a virtualenv relocatable this way breaks the no-site-packages isolation of the virtualenv as well as other aspects that come with relative paths and /usr/bin/env shebangs that may be undesirable.

Also, the .pth and .egg-link rewriting doesn't seem to work as intended. This attempts to overcome these issues and provide a way to easily clone an existing virtualenv.

It performs the following:

copies sys.argv[1] dir to sys.argv[2]

updates the hardcoded VIRTUAL_ENV variable in the activate script to the new repo location. (--relocatable doesn't touch this)

updates the shebangs of the various scripts in bin to the new Python if they pointed to the old Python. (version numbering is retained.)

it can also change /usr/bin/env python shebangs to be absolute too, though this functionality is not exposed at present.

checks sys.path of the cloned virtualenv and if any of the paths are from the old environment it finds any .pth or .egg link files within sys.path located in the new environment and makes sure any absolute paths to the old environment are updated to the new environment.

finally it double checks sys.path again and will fail if there are still paths from the old environment present.

NOTE: This script requires Python 2.7 or 3.4+

Answer 9

We can share storage for large modules between virtual environments by creating a hard link copy of the base environment, then updating paths using this venv_move script.

cd /opt
cp -al python3.10-ai python3.10-fastai
venv_move python3.10-fastai

The first argument is the path to the venv. It deletes any __pycache__ under that path.

It detects the old path, and replaces it with the current path, after confirming. Then it does similarly for the venv name in the activate scripts. It seems to work okay, even when moving to a different machine of the same type.

The script relies on bash and GNU sed, i.e. it works on Linux and not necessarily on Mac OS or Windows. It would make sense to re-write it in Python for non-Linux users.

#!/bin/bash -eu
venv=${1%/}

find "$venv" -name __pycache__ | xargs rm -rf --

old=`perl -ne '/VIRTUAL_ENV="(.*?)"/ && print "$1\n"' "$venv/bin/activate"`
new=$PWD/$venv

old2="(`basename "$old"`)"
new2="(`basename "$venv"`)"

if [ "$old" = "$new" ]; then
    echo "venv paths are already set correctly to $new"
else
    files=`fgrep -r "$old" "$venv" -l`
    echo "$files"
    echo "Replace $old with $new in the above files?"
    read -p "[yn] ? " YN
    if [ "$YN" = y ]; then
        sed -i "s:$old:$new:g" $files
    fi

    files=`fgrep -r "$old2" "$venv"/bin/activate* -l`
    echo "$files"
    echo "Replace $old2 with $new2 in the above files?"
    read -p "[yn] ? " YN
    if [ "$YN" = y ]; then
        sed -i "s:$old2:$new2:g" $files
    fi
fi

Answer 10

You can

Recently we had to delete some users at our servers, but some of them had legacy code. I knew it so I moved all the data to some new directory. A moment has come to run some legacy code using some legacy environment, but unfortunately it didn't work.

pip didn't work so I couldn't get a neat freeze requirements.txt, and I was super lazy to install packages one by one from lib/site-packages. So I decided to look for a workaround.

The workaround: I changed all the old environment paths in bin/activate* and bin/pip* files and also replaced bin/python* link referrals (the links were broken). It worked after it. Not sure if all the changes are obligatory, but still this information might be of use.

Answer 11

As said, there are ways to do so. The best tool so far should be venv-pack. One command to do so, while it does the hard work of removing the hardcoded VIRTUAL_ENV variable so once packed, the venv can be put into anywhere and still works.