I am developing a program inside a Python virtual environment. Running the command
python -m venv .venv
on Windows, puts the python symlink in .venv\Scripts\ while
python3 -m venv .venv
on macOS puts the symlinks on .venv/bin/. I'm using Visual Studio Code for development and there is a .vscode\\settings.json which needs to point towards the executable's symlinks. For example
{
"python.pythonPath": ".venv\\path\\to\\python",
}
How can I force the venv to put the symlinks in identical locations regardless of the platform?
P.S.1. The .venv folder is ignored by git and is included in the .gitignore file, as AFIK it is not a good practice to ship it with the codebase.
P.S.2. To avoid XY-problem, the final goal is to have an identical development environment on different platforms. Whatever the solution, regardless of the package manager, Visual Studio Code should be able to find the executable's symlinks on different platforms.
P.S.3. I need to find a way to change the __VENV_BIN_NAME__ parameter.
P.S.4. From here, one possible solution might be to use "python.pythonPath": "${env:PYTHON_INSTALL_LOC}", instead.
P.S.5. I asked another question here.
Two things. One, you can't have a virtual environment use bin/ on Windows (see the rejected idea).
Two, the Python extension is running an experiment to get rid of python.pythonPath which will solve your conflict. See the May release blog post for details and how to opt in.
Why does it matter where each OS puts the venv python? If you've correctly made sure that .venv is not in the code base but making sure it's in .gitignore than it doesn't matter if someone who loads up your code even need venv. It's good practice and guarantees that whoever has your code on whichever OS their python, with any dependencies your program needs, is going to be used.
If you are using multiple OS to develop than, create a workspace or project .vscode settings file with those specific settings to the python you want to use but also make sure that .vscode directory in your project is in your .gitignore. Then set up separate .vscode settings on different machines for those OS-specific settings.
This question already has answers here:
How to recreate a virtual env in python
(2 answers)
Closed 3 years ago.
I have two computers (running Ubuntu) that have access to one server. The shared home directory of the two computers is on the server.
On computer (A) python 3.5 is installed, on computer (B) python 3.7 is installed. I created a virtualenv from computer (B) on the shared home directory (using python 3.7).
Now although it is possible to activate that virtualenv from computer (A) it does not use the "virtualenv-python 3.7" but the system's python 3.5. So technically the virtualenv is activated but effectively it is not.
Note that the VIRTUAL_ENV path is set correctly.
I thought that virtualenv-folder is a fully enclosed environment, not even needing any python installed on the system. So why is it not working?
A virtualenv doesn't have a full Python installation. Instead, it links to an installation present on the system (FYI that link is in <env>/lib/orig-prefix.txt). The env's directory tree has some stubs and special logic but it uses the bulk from that installation.
So if you run activate on a system that doesn't have the same Python at the same path as the one virtualenv was created for, that script won't work correctly. It might happen to hook to something else present at the same path but this is not a supported scenario so all bets are off.
If you need a "fully enclosed environment", you may want to take a look at pyenv which does exactly that -- installs a full Python under your home dir. (Or you can just install Python from source to somewhere under your home dir -- but pyenv makes it easy to switch to that installation and back.)
The short answer is because on both computers A and B, the path to your python is likely just an alias. You can verify this by following the path on computer B and using the OS's GUI you can see it is a symlink to the actual python installation sitting somewhere else on your machine (probably usr/bin/). For example, on one machine where multiple installations of Python is found, I see that my virtual environment (.virtualenvs/revconnecion/include/python3.6) is an alias to the original /anaconda3/include/python3.6.
Solution:
You can create your virtual environment by specifying the python version itself when creating your environment:
python3.7 -m venv sharedvenv
or:
virtualenv -p python3.7
You can also manually change the symlinks / alias but the above method works better. Using the specific version of Python itself to create the virtual environment leaves no ambiguity and explicit is better than implicit.
Run which python on both Computer A and B to verify that it's pointing to the right version of Python.
I have compiled python sources with the --prefix option. After running make install the binaries are copied to a folder of my account's home directory.
I needed to rename this folder but when I use pip after the renaming it says that it can't find the python interpreter. It shows an absolute path to the previous path (before renaming).
Using grep I found out multiple references to absolute paths relative to the --prefix folder.
I tried to override it by setting the PATH,PYTHONPATH and PYTHONHOME environment variables but it's not better.
Is there a way to compile the python sources in a way that I can freely moves it after ?
Pip is a python script. Open it and see :
it begins with #!/usr/bin/python
You can either create a symbolic link in the old path to point to the new one, or replace the shebang with the new path. You can also keep your distrib interpreter safe by leaving it be and set the compiled one into a new virtualenv.
In my home, I have a directory named lib/python2.7 (there are actually five directories like that, for different python versions). Since this is a shared hosting (Webfaction), that directory is fundamental to me. There, I have stuff like virtualenv and virtualenvwrapper installed, since as customer of a shared hosting, I have no access to sudo and installing global packages.
However, when I create a virtualenv:
$ mkvirtualenv myenvironment
$ workon myenvironment
$ which pip
# outputs the myenvironment's path to pip
$ pip freeze
The command shows the whole packages list under my lib/python2.7 (this includes the same virtualenv packages, and conflicting packages I have due to... legacy... reasons). This also annoys me if I want to install a package which is the name of a package in lib/python2.7 since it does not allow me to update it.
Right inside the workon environment, I try to check whether the PYTHONPATH has weird stuff, but it is empty:
$ echo $PYTHONPATH
# shows a blank line
It is also empty if I try that command out of any virtual environment.
It seems that --no-site-packages is default but solves just part of the problem. This means: pip freeze | wc -l displays a lesser value when in an environment than when executing globally, out of any environment, which tells me that there are certain already-provided packages that are being excluded and are from the hosting itself (and not installed by me since, again, the hosting is shared and I don't have access to global space).
My question is: How can I solve this? I want my virtualenv not list the packages in $HOME/lib/python2.7
Please avoid dupe-linking to this question, nothing was useful there and still does not have an accepted answer. I wrote this question after reading and trying each solution in that question
I think you need to specify python version. You can specify python version with which you want to create virtual environment using command like
virtualenv -p /usr/bin/python3.4 virt/virtname --no-site-packages
Because when you not specify a python version, virtualenv creates a environment with pythonv2.7 and hence all packages end up in the folder you mentioned.
Found the solution after deeply digging. This is a Webfaction custom but this could apply to any installation like this if the problem occurs.
The core of the problem is that Webfaction configured a sitecustomize.py file for us. The file is located at /usr/local/lib/pythonX.Y/sitecustomize.py and adds by itself the contents of ~/lib/pythonX.Y (and conditionally the contents of any python app under ~/webapps if you are working under a directory of it to run a python script).
Even when the virtualenv's python executable is a different one, it will load the said sitecustomize.py file each time it runs as the base python executable does.
The workaround here? Create an empty sitecustomize.py in your virtualenv to override the other:
touch ~/.virtualenvs/yourvenv/lib/pythonX.Y/sitecustomize.py
And it will work. Take this as reference if you are stuck here like I was
Notes: Replace X.Y on each case with the corresponding version you are working. Additionally remember: You cannot remove or edit the base sitecustomize.py since you are in a shared hosting, in this case. However, overriding will work for each case as long as you do this for every virtualenv you want.
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.
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.
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:
python
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?])
python3 (convention for linux environments that dual install python 2 and 3)
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.
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.
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.
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).
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.
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.
The --relocatable argument to virtualenv appears to allow you to do this.
YES, YOU CAN! (In windows)
The workaround is easy, just move your virtual environment anywhere then edit activate.bat inside scripts\:
Move to the virtual environment to the desired directory
Right-click and edit activate.bat located at venv_folder\scripts.
Change VIRTUAL_ENV variable from:
set VIRTUAL_ENV=C:\old_directory\venv_name
into
set VIRTUAL_ENV=C:\new_directory\venv_name
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
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.
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.
I wrote a venv-move script.
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. It seems to work okay, even when moving to a different machine of the same type.
It would make sense to re-write this in Python, but the program would be longer.
#!/bin/bash -eu
venv=$1
old=`perl -ne '/VIRTUAL_ENV="(.*?)"/ && print "$1\n"' "$venv/bin/activate"`
new=$PWD/$venv
find "$venv" -name __pycache__ | xargs rm -rf --
files=`fgrep -r "$old" "$venv" -l`
echo "replace $old with $new in:"
echo "$files"
read -p "[yn] ? " YN
[ "$YN" = y ]
sed -i "s:$old:$new:g" $files
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+