How do I create a virtual environment for a specified version of Python?
38 Answers
Since Python 3, the documentation suggests creating the virtual environment using:
python3 -m venv "my_env_name"
Please note that venv does not permit creating virtual environments with other versions of Python. For that, install and use the virtualenv package.
Obsolete information
The pyvenv script can be used to create a virtual environment:
pyvenv "/path/to/new/virtual/environment"
Deprecated since Python 3.6.
[November 2019] I needed to install a Python 3.7 environment (env) on my Python 3.8-based Arch Linux system. Python 3.7 was no longer on the system, so I could not downgrade Python, to install a package that I needed.
Furthermore, I wanted to use that package / Python 3.7 inside a virtual environment (venv). This is how I did it.
Download Python version source files:
I downloaded the Python 3.7.4 source files from
to
/mnt/Vancouver/apps/python_versions/src/Python-3.7.4.tgz
I then extracted that archive (source files) to
/mnt/Vancouver/apps/python_versions/src/Python-3.7.4/
Installation:
[Note: in my system env, not a venv.]
cd /mnt/Vancouver/apps/python_versions/src/Python-3.7.4/
time ./configure ## 17 sec
time make ## 1 min 51 sec
time sudo make install ## 18 sec
time make clean ## 0.3 sec
Examine installed Python versions:
$ which python
/usr/bin/python
$ python --version
Python 3.8.0
$ which python3.7
/usr/local/bin/python3.7
$ python ## Python 3.8 [system / env]
Python 3.8.0 (default, Oct 23 2019, 18:51:26)
[GCC 9.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>
$ python3.7 ## newly-installed Python 3.7 package
Python 3.7.4 (default, Nov 20 2019, 11:36:53)
[GCC 9.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> print(sys.version)
3.7.4 (default, Nov 20 2019, 11:36:53)
[GCC 9.2.0]
>>>
$ python3.7 --version
Python 3.7.4
How to create a venv for a specific Python version:
https://docs.python.org/3/tutorial/venv.html
12.2. CREATING VIRTUAL ENVIRONMENTS
The module used to create and manage virtual environments is called
venv.venvwill usually install the most recent version of Python that you have available. If you have multiple versions of Python on your system, you can select a specific Python version by running python3 or whichever version you want.To create a virtual environment, decide upon a directory where you want to place it, and run the venv module as a script with the directory path:
python3 -m venv tutorial-envThis will create the
tutorial-envdirectory if it doesn’t exist, and also create directories inside it containing a copy of the Python interpreter, the standard library, and various supporting files. ...
Create Python 3.7 venv [on a Python 3.8 operating env / system]:
python3.7 -m venv ~/venv/py3.7 ## create Python 3.7-based venv
source ~/venv/py3.7/bin/activate ## activate that venv
deactivate ## deactivate that venv (when done, there)
Added to ~/.bashrc:
alias p37='echo " [Python 3.7 venv (source ~/venv/py3.7/bin/activate)]" && source ~/venv/py3.7/bin/activate'
Test Python 3.7 venv:
$ p37
[Python 3.7 venv (source ~/venv/py3.7/bin/activate)]
(py3.7)$ python --version
Python 3.7.4
(py3.7)$ python
Python 3.7.4 (default, Nov 20 2019, 11:36:53)
[GCC 9.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> print(sys.version)
3.7.4 (default, Nov 20 2019, 11:36:53)
[GCC 9.2.0]
>>>
You should have that Python version installed. If you have it then basically,
With virtualenv,
virtualenv --python=python3.8 env/place/you/want/to/save/to
with venv
python3.8 -m venv env/place/you/want/to/save/to
The above examples are for python3.8, you can change it to have different versions of virtual environments given that they are installed in your computer.
These two commands should work fine.
virtualenv -p python2 myenv (For python2)
virtualenv -p python3 myenv (For python3)
For Mac(High Sierra), install the virtualenv on python3 and create a virtualenv for python2:
$ python3 -m pip install virtualenv
$ python3 -m virtualenv --python=python2 vp27
$ source vp27/bin/activate
(vp27)$ python --version
Python 2.7.14
As already mentioned in multiple answers, using virtualenv is a clean solution. However a small pitfall that everyone should be aware of is that if an alias for python is set in bash_aliases like:
python=python3.6
this alias will also be used inside the virtual environment. So in this scenario running python -V inside the virtual env will always output 3.6 regardless of what interpreter is used to create the environment:
virtualenv venv --python=pythonX.X
These seem a little overcomplicated for Windows. If you're on Windows running python 3.3 or later, you can use the python launcher py to do this much more easily. Simply install the different python version, then run:
py -[my version] -m venv env
This will create a virtual environment called env in your current directory, using python [my version]. As an example:
py -3.7 -m venv env
./env/Scripts/activate
This creates a virtual environment called env using python3.7 and activates it. No paths or other complex stuff required.
I utilized this answer for Windows
https://stackoverflow.com/a/22793687/15435022
py -3.4 -m venv c:\path\to\wherever\you\want\it
I use pyenv to manage my python version.
pyenv install 3.7.3
pyenv local 3.7.3
Check your python version:
$ python --version
Python 3.7.3
Create the virtual environment with venv:
python -m venv .
Then activate the Virtual Environment:
source bin/activate
Check your python version:
$ python --version
Python 3.7.3
You may need to remove the previous virtual environment
rm -rf bin
End of 2020:
The most seamless experience for using virtualenv (added benefit: with any possible python version) would be to use pyenv and its (bundled) pyenv-virtualenv plugin (cf https://realpython.com/intro-to-pyenv/#virtual-environments-and-pyenv)
Usage: pyenv virtualenv <python_version> <environment_name>
Installation:
- first check that you've got all prerequisites (depending on your OS): https://github.com/pyenv/pyenv/wiki/Common-build-problems#prerequisites
curl https://pyenv.run | bashexec $SHELL
cf https://github.com/pyenv/pyenv-installer
That being said, nowadays the best possible alternative instead of using virtualenv (and pip) would be Poetry (along with pyenv indicated above, to handle different python versions).
Another option, because it's supported directly by the PyPA (the org behind pip and the PyPI) and has restarted releasing since the end of May (didn't release since late 2018 prior to that...) would be Pipenv
This worked for my usage in Windows 10, where I have Python 3.7 and want to downgrade for a project in Python 3.6.6:
I used "venv" to create a new environment called "venv", I downloaded from https://www.python.org/downloads/windows/ ; install "Download Windows x86-64 executable installer-" ; then I used the following command line in the directory where I want to create my environment
>C:\Users\...\Python\Python36\python.exe -m venv venv
Finally, I activated the environnent using the command line:
>venv\Scripts\activate.bat
And check the python version by calling:
>python --version
Python 3.6.6
On Linux Ubuntu 21.04 (currently Python 3.9.5) I needed to get a virtualenv of Python 3.7.8. Full steps to get working:
Find the Python version source you want, for example 3.7.8 is here: https://www.python.org/downloads/release/python-378/
Download the Gzipped source tarball
Unzip it with tar zxvf Python-3.7.8.tgz (amend as required with your version number if different from 3.7.8)
Copy the unzipped folder to /usr/bin with: sudo cp -r Python-3.7.8 /usr/bin
cd /usr/bin/Python-3.7.8/
Check the contents if you wanted to see what you have so far: ls
sudo time ./configure
sudo time make
time sudo make install
time make clean
Check how your python is set up and reporting:
which python
python --version
Should be all relating to your primary install (Python 3.9.5 for me)
To check your new install:
which python 3.7
python3.7 --version
Should be all relating to your 3.7.8 install
If you want to run it to check, do:
python3.7
exit()
Install venv:
sudo apt install venv
To create a venv (maybe in your repo, if so, add .venv to .gitignore):
python3.7 -m venv .venv
To activate your venv:
source .venv/bin/activate
Check your version:
python --version
This was a bug with virtualenv. Just upgrading your pip should be the fix.
pip install --upgrade virtualenv
I use Windows so I should use .exe on the pthon path
virtualenv -p=C:\Python27\python2.exe <envname>
For Debian (debian 9) Systems in 2019, I discovered a simple solution that may solve the problem from within the virtual environment.
Suppose the virtual environment were created via:
python3.7 -m venv myenv
but only has versions of python2 and python2.7, and you need the recent features of python3.7.
Then, simply running the command:
(myvenv) $ python3.7 -m venv --upgrade /home/username/path/to/myvenv/
will add python3.7 packages if they are already available on your system.
It worked for me on windows with python 2 installation :
- Step 1: Install python 3 version .
- Step 2: create a env folder for the virtual environment.
- Step 3 : c:\Python37\python -m venv c:\path\to\env.
This is how i created Python 3 virtual environment on my existing python 2 installation.
Yes you just need to install the other version of python, and define the location of your other version of python in your command like :
virtualenv /home/payroll/Documents/env -p /usr/bin/python3
Here is the stepbystep how to create the Virtual environment in Visual Studio Code folder:
I used Powershell (Administrator mode):
1. I create a VSCode folder - "D:\Code_Python_VE" where I want to create Virtual environment.
2. Next I type the command - "pip3 install virtualenv". (D:\Code_Python_VE> pip3 install virtualenv)
3. D:\Code_Python_VE> python3 -m venv project_env
4. D:\Code_Python_VE>project_env\Scripts\activate.bat
5. D:\Code_Python_VE> ls - This will list a new directory "project_env".
6. D:\Code_Python_VE> code . This will start Visual Studio Code. Make sure the command is (code .).
7. Create launch.jason with following content:
{
// Use IntelliSense to learn about possible attributes.
// Hover to view descriptions of existing attributes.
// For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
"version": "0.2.0",
"configurations": [
{
"type": "python",
"request": "launch",
"name": "Python: Current File (Integrated Terminal 1)",
"program": "${file}"
},
{
"name": "Python: Current File (Integrated Terminal 2)",
"type": "python",
"request": "launch",
"program": "${file}",
"console": "integratedTerminal"
}
]
}
(Please search how to go to Debug window and Add new Configuration in VS Code).
- Press F1 in Visual studio code and the command pallet will open - Select Python Interpreter and select the virtual environment project_env.
- Add test.py file with one statement print("Hello World").
- Run this program.
- In Visual studio Code terminal -
(project_env) d:\Code_Python_VE>python -m pip install --upgrade
I hope this helps.
UBUNTU 19.04 / Global Python 3.7.
This worked for me, enabling a Python 3.8 environment using the recommended venv for python 3 development.
Install 3.8 and 3.8 venv module:
$ sudo apt install python3.8 python3.8-venv
plus any other modules you need
Create your Virtual Env using the python version you want in that env
$ /usr/bin/python3.8 -m venv python38-env
switch into your virtual env
$ source python38-env/bin/activate
python -V = python 3.8
Surprised that no one has mentioned conda so far. I have found this is a lot more straightforward than the other methods mentioned here. Let's say I have python 3.9 and python 2.7 and a project I am working on was python 3.5.4, I could simply create the isolated virtual env for 3.5.4 with the conda command without downloading anything else.
To see a list of available python versions first, use the command
conda search "^python$"
To create the virtual environment for python version x.y.z, use the command
conda create -n yourenvname python=x.y.z
Activate venv with
conda activate yourenvname
Deactivate with
conda deactivate
To delete the virtual environment when done, use the command
conda remove -n yourenvname --all
Answer to this question shouldn't be that complicated...
TL,DR:
install as many versions of python you prefer on your system and use:
/c/path/to/any/version/of/python -m venv my_venv
============================================
I use venv to install virtual environments with
python -m venv <where/to/and/name_of_venv>
if you try which python you will see which python you are referring to, when saying "python". for example, for me it is:
which python
result: /c/Program Files/Python36/python
So, now you have the answer!
you can install any version of python on your system and have multiple of them at the same time. So, for example I installed Python3.7 in this directory: "C:\Program Files\Python37".
So, instead of using 'python' now I specify which python by /c/Program\ Files/Python37/python:
/c/Program\ Files/Python37/python -m venv my_venv
(don't forget to escape the space in the path)
That's it!
sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt update
sudo apt install python_version (ex: sudo apt install python3.8)
python_version -m venv env (ex: python3.8 -m venv env)
. env/bin/activate
This Above steps will solve your python version for env issue.
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