Using virtualenv, I run my projects with the default version of Python (2.7). On one project, I need to use Python 3.4.
brew install python3 to install it on my Mac. Now, how do I create a virtualenv that uses the new version?
e.g. sudo virtualenv envPython3
If I try:
virtualenv -p python3 test
Running virtualenv with interpreter /usr/local/bin/python3 Using base prefix '/usr/local/Cellar/python3/3.4.0_1/Frameworks/Python.framework/Versions/3.4' New python executable in test/bin/python3.4 Also creating executable in test/bin/python Failed to import the site module Traceback (most recent call last): File "/Users/user/Documents/workspace/test/test/bin/../lib/python3.4/site.py", line 67, in <module> import os File "/Users/user/Documents/workspace/test/test/bin/../lib/python3.4/os.py", line 634, in <module> from _collections_abc import MutableMapping ImportError: No module named '_collections_abc' ERROR: The executable test/bin/python3.4 is not functioning ERROR: It thinks sys.prefix is '/Users/user/Documents/workspace/test' (should be '/Users/user/Documents/workspace/test/test') ERROR: virtualenv is not compatible with this system or executable
virtualenv -p python3 envname
Update after OP’s edit:
There was a bug in the OP’s version of virtualenv, as described here. The problem was fixed by running:
pip install --upgrade virtualenv
Python 3 has a built-in support for virtual environments – venv. It might be better to use that instead. Referring to the docs:
Creation of virtual environments is done by executing the pyvenv
Update for Python 3.6 and newer:
python3 -m venv /path/to/new/virtual/environment
In addition to the other answers, I recommend checking what instance of virtualenv you are executing:
If this turns up something in /usr/local/bin, then it is possible – even likely – that you installed virtualenv (possibly using an instance of easy_tools or pip) without using your system’s package manager (brew in OP’s case). This was my problem.
Years ago – when I was even more ignorant – I had installed virtualenv and it was masking my system’s package-provided virtualenv.
After removing this old, broken virtualenv, my problems went away.
I’v tried pyenv and it’s very handy for switching python versions (global, local in folder or in the virtualenv):
brew install pyenv
then install Python version you want:
pyenv install 3.5.0
and simply create virtualenv with path to needed interpreter version:
virtualenv -p /Users/johnny/.pyenv/versions/3.5.0/bin/python3.5 myenv
That’s it, check the version:
. ./myenv/bin/activate && python -V
There are also plugin for pyenv pyenv-virtualenv but it didn’t work for me somehow.
It worked for me
virtualenv --no-site-packages --distribute -p /usr/bin/python3 ~/.virtualenvs/py3
virtualenv --python=/usr/bin/python3 <name of env>
worked for me.
If you install python3 (
brew install python3) along with virtualenv burrito, you can then do
mkvirtualenv -p $(which python3) env_name
Of course, I know virtualenv burrito is just a wrapper, but it has served me well over the years, reducing some learning curves.
sudo apt-get install python3 python3-pip virtualenvwrapper
Create a Python3 based virtual environment. Optionally enable
mkvirtualenv -p /usr/bin/python3 <venv-name>
Set into the virtual environment.
Install other requirements using
pip package manager.
pip install -r requirements.txt pip install <package_name>
When working on multiple python projects simultaneously it is usually recommended to install common packages like
pdbpp globally and then reuse them in virtualenvs.
Using this technique saves a lot of time spent on fetching packages and installing them, apart from consuming minimal disk space and network bandwidth.
sudo -H pip3 -v install pdbpp mkvirtualenv -p $(which python3) --system-site-packages <venv-name>
If there are a lot of system wide python packages then it is recommended to not use
--system-site-packages flag especially during development since I have noticed that it slows down Django startup a lot. I presume Django environment initialisation is manually scanning and appending all site packages from the system path which might be the reason. Even
python manage.py shell becomes very slow.
Having said that experiment which option works better. Might be safe to just skip
--system-site-packages flag for Django projects.
I tried all the above stuff, it still didn’t work. So as a brute force, I just re-installed the anaconda, re-installed the virtualenv… and it worked.
Amans-MacBook-Pro:~ amanmadan$ pip install virtualenv You are using pip version 6.1.1, however version 8.1.2 is available. You should consider upgrading via the 'pip install --upgrade pip' command. Collecting virtualenv Downloading virtualenv-15.0.3-py2.py3-none-any.whl (3.5MB) 100% |████████████████████████████████| 3.5MB 114kB/s Installing collected packages: virtualenv Successfully installed virtualenv-15.0.3 Amans-MacBook-Pro:python amanmadan$ virtualenv my_env New python executable in /Users/amanmadan/Documents/HadoopStuff/python/my_env/bin/python Installing setuptools, pip, wheel...done. Amans-MacBook-Pro:python amanmadan$
On Mac I had to do the following to get it to work.
mkvirtualenv --python=/usr/bin/python3 YourEnvNameHere
Python now comes with its own implementation of virtual environment, by the name of “venv”. I would suggest using that, instead of virtualenv.
Quoting from venv – docs,
Deprecated since version 3.6: pyvenv was the recommended tool for
creating virtual environments for Python 3.3 and 3.4, and is
deprecated in Python 3.6.
Changed in version 3.5: The use of venv is now recommended for
creating virtual environments.
For windows, to initiate venv on some project, open cmd:
python -m venv "c:pathtomyenv"
(Would suggest using double quote around directory path if it contains any spaces. Ex: “C:/My Dox/Spaced Directory/Something”)
Once venv is set up, you will see some new folders inside your project directory. One of them would be “Scripts”.
To activate or invoke venv you need:
You can deactivate a virtual environment by typing “deactivate” in your shell. With this, you are now ready to install your project specific libraries, which will reside under the folder “Lib”.
================================ Edit 1 ====================================
The scenario which will be discussed below is not what originally asked, just adding this in case someone use vscode with python extension
In case, you use vs code with its python extension, you might face an issue with its pylint which points to the global installation. In this case, pylint won’t be able to see the modules that are installed in your virtual environment and hence will show errors while importing.
Here is a simple method to get past this.
cd WorkspaceScripts .Activate.ps1 code .
We are basically activating the environment first and then invoking vs-code so that pylint starts within the environment and can see all local packages.
virtualenv --python=/usr/local/bin/python3 <VIRTUAL ENV NAME>
this will add python3
path for your virtual enviroment.
For those having troubles while working with Anaconda3 (Python 3).
You could use
conda create -n name_of_your_virtualenv python=python_version
To activate the environment ( Linux, MacOS)
source activate name_of_your_virtualenv
I wanted to keep python 2.7.5 as default version on Centos 7 but have python 3.6.1 in a virtual environment running alongside other virtual environments in python 2.x
I found the below link the best solution for the newest python version ( python 3.6.1)
It shows the steps for different platforms but the basic steps are
I got the same error due to it being a conflict with miniconda3 install so when you type “which virtualenv” and if you’ve installed miniconda and it’s pointing to that install you can either remove it (if your like me and haven’t moved to it yet) or change your environment variable to point to the install you want.
I had the same
ERROR message. tbrisker’s solution did not work in my case. Instead this solved the issue:
$ python3 -m venv .env
You can specify specific Version of Python while creating environment.
It’s mentioned in virtualenv.py
virtualenv --python=python3.5 envname
In some cases this has to be the full path to the executable:
virtualenv --python=/Users/username/.pyenv/versions/3.6.0/bin/python3.6 envname
parser.add_option( '-p', '--python', dest='python', metavar='PYTHON_EXE', help='The Python interpreter to use, e.g., --python=python3.5 will use the python3.5 ' 'interpreter to create the new environment. The default is the interpreter that ' 'virtualenv was installed with (%s)' % sys.executable)
In python3.6 I tried
python3 -m venv myenv,
as per the documentation, but it was taking so long. So the very simple and quick command is
python -m venv yourenv
It worked for me on python3.6.
For those of you who are using pipenv and want to install specific version:
pipenv install --python 3.6
This is all you need, in order to run a virtual environment in python / python3
virtualenv not installed, run
pip3 install virtualenv
virtualenv -p python3 <env name>
Sometime the cmd
virtualenv fails, if so use this:
python3 -m virtualenv <env_name> # you can specify full path instead <env_name> to install the file in a different location other than the current location
Now activate the virtual env:
You should see the full path to your dir and
To exit the virtualenv, run:
On Windows command line, the following worked for me. First find out where your python executables are located:
This will output the paths to the different python.exe on your system. Here were mine:
So for Python3, this was located in the first path for me, so I cd to the root folder of the application where I want to create a virtual environment folder. Then I run the following which includes the path to my Python3 executable, naming my virtual environment ‘venv’:
virtualenv --python=/Users/carandangc/Anaconda3/python.exe venv
Next, activate the virtual environment:
Finally, install the dependencies for this virtual environment:
pip install -r requirements.txt
This requirements.txt could be populated manually if you know the libraries/modules needed for your application in the virtual environment. If you had the application running in another environment, then you can automatically produce the dependencies by running the following (cd to the application folder in the environment where it is working):
pip freeze > requirements.txt
Then once you have the requirements.txt that you have ‘frozen’, then you can install the requirements on another machine or clean environment with the following (after cd to the application folder):
pip install -r requirements.txt
To see your python version in the virtual environment, run:
Then voila…you have your Python3 running in your virtual environment. Output for me:
The below simple commands can create a virtual env with version 3.5
apt-get install python3-venv python3.5 -m venv <your env name>
if you want virtual env version as 3.6
python3.6 -m venv <your env name>