I have been through numerous similar questions and I still don't understand how are we activating virtual environment for Django projects. Please mention explanation for how each command works and one more questions is that why do we not need to install python in Django's virtual environment, I am getting confused. Thank you in advance, please help this newbie.
Benefits
You can use any version of python you want for a specific environment
without having to worry about collisions (shoutout to my python 2.7
mac users!)
You can organize your packages much better and know exactly the
packages you need to run your code incase someone else needs to run
it on their machine
Your main python package directory does not get FLOODED with
unnecessary python packages
To create virtual environment
step 1 install environment package (virtualenv) using pip
pip install virtualenv
step 2 create virtualenv
virtualenv env_name #<- env_name is virtualenv name you can set any
step 3 Activate Virtual env
env_name\Scripts\activate #<- for window
step 4 Install pakages you wan to install in virtual env
cmd(env_name): pip install django
Note that python is install in your virtual env automaticaty the
version is same as in your local machine
There is no difference between activating virtual environment for Django or for other purposes. Django on it's own does not differ from any Python library out there.
Python virtual environment allows you to separate your system Python and it's libraries and create self-contained directory tree that contains a Python installation for a particular version of Python, plus a number of additional packages.
On Linux, assuming you already have Python 3 and pip3 installed:
# install virtualenv package (skip if you have it already)
pip3 install virtualenv
# create virtual environment in directory "tutorial-env"
python3 -m venv tutorial-env
# activate virtual environment
source tutorial-env/bin/activate
Upon activation below command should give path to new Python binary:
which python3
Similarly with pip3
which pip3
As long as your environment is activate you can run pip3 install $package_name and it will install it inside virtual environment.
To deactivate your virtual environment:
deactivate
For more info and commands for Windows:
https://packaging.python.org/en/latest/guides/installing-using-pip-and-virtual-environments/
https://docs.python.org/3/tutorial/venv.html
Pip Freeze shows all the libraries I have on my computer not just the libraries in the virtual environment.
I am trying to create a requirements.txt file for my virtual environment. I'm using an anaconda distribution. I am creating a flask app. I have navigated to my project folder created the virtual environment added flask and then when I make the command pip freeze it clearly shows items that are not in my virtual environment like xlwings, pandas and stuff I use that has nothing to do with flask.
Any way I can create a requirements file from my virtual environment.
I can clearly see my virtual environment is active with (venv) to the left.
Edit: I created a short video showing I get the same list of libraries whether I'm in my virtual environment or not. Also I'm showing the site-packages in my virtual environment and showing that these libraries aren't there I'm specifically pointing out xlwings.
https://youtu.be/xEFZ3dSaqoY
So i'm not sure why it was happening, but I deleted the virtual environment and re-created it (I had a previous requirements.txt that was correct). Then I ran pip freeze again and it all worked. Not sure what happened, but it works for me now.
I had this same problem and it happened because i change the name of my venv folder.
To solve this i used this command in my terminal [yourVenv]\Scripts\python -m pip freeze.
If you don't want to do it like this everytime, try creating a new enviorment like this.
[yourVenv]\Scripts\python -m pip freeze > requirements.txt
python -m venv [yourVenv]
[yourVenv]\Scripts\activate
python -m pip install --upgrade pip
pip install -r requirements.txt
You need to activate your pip environment in the console that you are trying to run pip freeze in. That way it uses the environment's pip and not your global pip.
So in your console, navigate to your virtual environment folder. From there go to the "Scripts" folder. Then enter the word "activate" into the console.
You should then see next to the console cursor the name of your virtual environment. At that point you can use the pip that's inside of your virtual environment and all the normal pip commands will point to it.
In my case i was using vscode IDE so when i created .venv its recommended use worksapce, so i choosed yes thats why its took all from my system' lib.
for this you can delete old on .venv and create new one, this time don't choose plugin's recommendations.
for create veirtual enviroment in window/linx
python -m venv .venv or python3 -m venv .venv
to activate .venv win use (.venv\scripts\activate)
and for linux use (source .venv/bin/activate)
all command like pip freeze, pip list, pip freeze > requirements.txt will work
I have activated the python virtual environment, but anyway when I run pip install *, the dependencies are installed to my local Python path. The same happens when I run the server in my Django project: python manage.py runserver -> the system is not using the virtual environment, but the python from my PC. What is the problem? Why my activated virtual environment does not work?
I am using MacOS. Everything worked until I erased all my data and installed again Python.
Thank you!
If the packages aren't getting installed within your virtual environment, it most likely is the case that you are not using the pip within your virtual environment (or may not have pip within your virtual environment at all, in which case it is defaulting to use the pip installed in /usr/local/bin/). First, check that you have a separate version of pip in your virtual environment located in ./your_virtual_environment_name/bin/pip....If you don't, install from the PyPA download page (https://pip.pypa.io/en/stable/installing/#installing-with-get-pip-py). When you go to install a package within your virtual environment, activate the virtual environment first using source ./bin/activate inside your virtual environment, then "cd .." and you'll use the pip installed within the virtual environment by typing: ./your_virtual_environment_name/bin/pip install * ....The installation will be in ./your_virtual_environment_name/lib/python3.6/site-packages/
I've created a Python virtual environment, and activate it by doing:
joe#joe-mint $ source ./venvs/deep-learning/bin/activate
Which turns the prompt into:
(deep-learning) joe#joe-mint $
Now whenever I run a python package or try to install one, the system seems to ignore the fact that it's in a virtual environment and does things system-wide:
(deep-learning) joe#joe-mint $ which pip
/usr/local/bin/pip
The same happens when I try to install new packages that aren't on my system; it installs them to the system files (i.e. /usr/bin) instead of the virtual environment.
What's wrong with my virtual environment? How do I get it to ignore system files and do everything inside the environment?
I've looked at this question which says to use an explicit flag when creating the virtual environment to make it use the local environment packages, but I used python-3.5 -m venv to create the virtual environment, and this flag is removed in this version as it's now a default option.
I've also looked at this question and can confirm that the VIRTUAL_ENV variable is set correctly in the activate file of the virtual environment.
Here was the problem:
It seems that if you run pip on a venv without a local pip installation, then it will default to the system's pip outside the venv. Even if you've activated a virtual environment, this seems to want to install packages on the system rather than in the venv.
Here was the solution:
First, I had to install the virtual environment without pip due to a bug that has long remained unresolved.
Second, I installed pip in the virtual environment as per the instruction here. However, doing so required using some temporary folders that for some reason my user didn't have access to. So this failed, and the only way I could get it to work was to become root.
sudo su
activate ..../venvs/deep-learning/bin/activate to activate the virtual environment.
curl --silent --show-error --retry 5 https://bootstrap.pypa.io/get-pip.py | python as per the answer linked above.
Although which pip now indicated the correct pip (inside the venv) was being used, running pip would use the system one! Deactivating (deactivate) and reactivating the venv solved this.
Now it took me a while to realise that having installed this as root caused me permission errors when trying to install more packages using pip inside the virtual environment.
chown <user>:<group> -R ..../venvs/deep-learning/*
And that was it. After these steps, I could activate the venv and run pip correctly. It would use the pip inside the venv, and install packages inside the venv.
Using virtualenv, I run my projects with the default version of Python (2.7). On one project, I need to use Python 3.4.
I used 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
I get:
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
simply run
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
script:
pyvenv /path/to/new/virtual/environment
Update for Python 3.6 and newer:
As pawciobiel correctly comments, pyvenv is deprecated as of Python 3.6 and the new way is:
python3 -m venv /path/to/new/virtual/environment
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.
Install prerequisites.
sudo apt-get install python3 python3-pip virtualenvwrapper
Create a Python3 based virtual environment. Optionally enable --system-site-packages flag.
mkvirtualenv -p /usr/bin/python3 <venv-name>
Set into the virtual environment.
workon <venv-name>
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>
Django specific instructions
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.
virtualenv --python=/usr/bin/python3 <name of env>
worked for me.
This is all you need, in order to run a virtual environment in python / python3
First if virtualenv not installed, run
pip3 install virtualenv
Now Run:
virtualenv -p python3 <env name> # you can specify full path instead <env_name> to install the files in a different location other than the current location
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 files in a different location other than the current location
Now activate the virtual env:
source <env_name>/bin/activate
Or:
source `pwd`/<env_name>/bin/activate
Now run
which python
You should see the full path to your dir and <env_name>/bin/python suffix
To exit the virtualenv, run:
deactivate
To troubleshoot Python location got to here
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
How -p works
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)
I had the same ERROR message. tbrisker's solution did not work in my case. Instead this solved the issue:
$ python3 -m venv .env
In addition to the other answers, I recommend checking what instance of virtualenv you are executing:
which virtualenv
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.
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>
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:\path\to\myenv"
(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:
C:\> <venv>\Scripts\activate.bat
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 Workspace\Scripts
.\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.
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.
On Mac I had to do the following to get it to work.
mkvirtualenv --python=/usr/bin/python3 YourEnvNameHere
If you install python3 (brew install python3) along with virtualenv burrito, you can then do mkvirtualenv -p $(which python3) env_name
Of course, I know virtualenv burrito is just a wrapper, but it has served me well over the years, reducing some learning curves.
virtualenv --python=/usr/local/bin/python3 <VIRTUAL ENV NAME>
this will add python3
path for your virtual enviroment.
It worked for me
virtualenv --no-site-packages --distribute -p /usr/bin/python3 ~/.virtualenvs/py3
For those having troubles while working with Anaconda3 (Python 3).
You could use
conda create -n name_of_your_virtualenv python=python_version
To activate the environment ( Linux, MacOS)
source activate name_of_your_virtualenv
For Windows
activate name_of_your_virtualenv
I tried all the above stuff, it still didn't work. So as a brute force, I just re-installed the anaconda, re-installed the virtualenv... and it worked.
Amans-MacBook-Pro:~ amanmadan$ 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$
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)
https://www.digitalocean.com/community/tutorial_series/how-to-install-and-set-up-a-local-programming-environment-for-python-3.
It shows the steps for different platforms but the basic steps are
Install python3.x (if not present) for your platform
Install python3.x-devel for your platform
Create virtual environment in python 3.x
(for example $ python3.6 -m venv virenv_test_p3/ )
Activate the testenvironment for python 3.x
(for example source virenv_test_p3/bin/activate)
Install the packages which you want to use in your new python 3 virtual environment and which are supported ( for example pip install Django==1.11.2)
On Windows command line, the following worked for me. First find out where your python executables are located:
where python
This will output the paths to the different python.exe on your system. Here were mine:
C:\Users\carandangc\Anaconda3\python.exe
C:\Python27\python.exe
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:
call venv\Scripts\activate.bat
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:
python --version
Then voila...you have your Python3 running in your virtual environment. Output for me:
Python 3.7.2
For those of you who are using pipenv and want to install specific version:
pipenv install --python 3.6
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.