Develop Reference

zsh doesn't find workon from virtualenvwrapper

hi i have installed virtualenv python library to manage my env doing all the setup but when i use the following command to open my env that happen
francesco#AirdiFrancesco ~ % workon
zsh: command not found: workon
but when i run this code before workon don't give me problems
export WORKON_HOME=~/Envs
VIRTUALENVWRAPPER_PYTHON=$(which python3)
source /opt/homebrew/bin/virtualenvwrapper.sh
now i have tried to add this three line to my ~/zshch file but doesn't work. where i need to put this code in my bash?

How to deactivate venv while using fish?

I have installed venv using python3 with fish like and activated using env/bin/activate.fish, but there is no deactivate.fish in env/bin/
➜ ls env/bin/
activate activate.fish easy_install pip pip3.7 python3
activate.csh chardetect easy_install-3.7 pip3 python yapf
how can I deactivate venv?

In opposite to activate, deactivate is implemented as a shell function, not as a shell script or binary in env/bin. You can verify that by running:
type -t deactivate
function
To run the function and deactivate the virtualenv, just run deactivate
PS: This behaviour is the same for all shells, it is not special to fish.

Virtual environment doesn't work on Cloud9

Cloud9 (an online ide) doesn't seem to support my virtual environment:
me:~/workspace/dir (master) $ source venv/bin/activate
(venv) me:~/workspace/dir (master) $ which python
/usr/bin/python
This same virtual directory worked fine on my local machine:
(venv) me$ which python
/Users/me/dir2/dir/venv/bin/python
How can I fix this?

The following works for me.
sudo apt-get install python3.5-venv
python3.5 -m venv --clear ./mypy3.5/
source ./mypy3.5/bin/activate
It uses the
(mypy3.5) $ which python
/home/ubuntu/mypy3.5/bin/python
But there is a gotcha which might have been your problem. The python3 -m venv uses soft links to how your python resolves in your environment. I had Python 3.3, 3.4 and 3.5 installed in /usr/local so the /usr/local/bin/python3 would change and break my Python3 venv. Note that "python3" is evaluated for the environment not for an absolute path. To be careful, when there are more than one Python 3 on you system, create your virtual environment with an explicit path like the following.
/usr/bin/python3.5 -m venv --clear ./mypy3.5/
source ./mypy3.5/bin/activate
ls -l $(which python3.5)
/home/ubuntu/mypy3.5/bin/python3.5 -> /usr/bin/python3.5*

How do I run globally installed Jupyter from within virtual environments?

I'm trying to run Jupyter notebooks with a globally installed version of Jupyter from within virtual environments (using virtualenvwrapper, because I want to manage versions of installed packages). And I do not what to use Anaconda.
The problem is when I run jupyter notebook from within the virtualenv, it cannot find the packages installed in the env, it only finds the packages installed globally.
How do I set up Jupyter to check for packages installed within the virtual environment instead of globally?
Here is what I get when I run which python and which jupyter:
globally:
which python >>> /usr/local/bin/python
which jupyter >>> /usr/local/bin/jupyter
from within virtualenv:
which python >>> /Users/brianclifton/.virtualenvs/test/bin/python
which jupyter >>> /usr/local/bin/jupyter
running jupyter notebook from within the virtualenv:
which python >>> /usr/local/bin/python
which jupyter >>> /usr/local/bin/jupyter
Also, here is my .bash_profile:
export VISUAL=vim
export EDITOR="$VISUAL"
export PS1="\\[\[\e[38;5;94m\][\u] \[\e[38;5;240m\]\w:\[\e[m\] \$(__git_ps1 '(%s)')$ "
export CLICOLOR=1
export LSCOLORS=ExFxBxDxCxegedabagacad
export PATH=/usr/local/bin/python:/usr/local/bin:$PATH
alias ls='ls -GFh'
alias pserv="python -m SimpleHTTPServer"
alias ipynb="jupyter notebook"
export WORKON_HOME=/Users/brianclifton/.virtualenvs
export PROJECT_HOME=/Users/brianclifton/dev
source /usr/local/bin/virtualenvwrapper.sh
if [ -f $(brew --prefix)/etc/bash_completion ]; then
. $(brew --prefix)/etc/bash_completion
fi
alias branch='git rev-parse --abbrev-ref HEAD'
function frameworkpython {
if [[ ! -z "$VIRTUAL_ENV" ]]; then
PYTHONHOME=$VIRTUAL_ENV /usr/local/bin/python "$#"
else
/usr/local/bin/python "$#"
fi
}

Another solution from virtualenv doc
workon test
pip install ipykernel
python -m ipykernel install --prefix=/usr/local --name test-kernel
Then your kernel should appear when you run jupyter from your other virtualenv, and all the packages installed in test would be available from it. Change prefix value according to the doc if you prefer a per-user installation instead of system-wide

One possible solution is to prefix your virutalenv's bin directory to your path. This way jupyter will find the virtualenv's libraries. You can do this by running export PATH:`which python`:$PATH after you activate your environment. It would be easy enough to alias.
However, a better solution may be to add this line to the postactivate hook/script. To find the location of this script do ls $WORKON_HOME after activate virtualenvwrapper and edit $WORKON_HOME/<virtualenv_name>/bin/postactivate.

A strange virtualenv issue-- even with -p it installs multiple pythons

I'm trying to create a virtual environment with 3.4. I have followed instructions found through searching stackoverflow, as well as posting this issue on reddit, and continue to have the same problem: even when I specify python3.4, it installs both 3.4 AND 2.7. This then leads to all of the problems I was trying to avoid by using a virtual environment in the first place.
$ which python3
/Library/Frameworks/Python.framework/Versions/3.4/bin/python3
$ mkdir test
$ cd test
$ virtualenv -p /Library/Frameworks/Python.framework/Versions/3.4/bin/python3.4 venv
(various output saying it's creating venv/bin/python with 3.4)
$ source venv/bin/activate
(venv)$ python --version
Python 2.7.9
when I look in the venv/bin folder it has binaries for both 2.7.9 and 3.4.
after activating the environment:
$ echo $PATH
/Users/theinevitable/Documents/python/test/venv/bin:/Library/Frameworks/Python.framework/Versions/3.4/bin:/Library/Frameworks/Python.framework/Versions/2.7/bin:/Library/Frameworks/Python.framework/Versions/3.4/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin:/Applications/Postgres.app/Contents/Versions/9.4/bin
$ which python
/Users/theinevitable/Documents/python/test/venv/bin/python
$ which python3
/Library/Frameworks/Python.framework/Versions/3.4/bin/python3
one person on reddit suggested trying to use venv instead:
$ python3.4 -m venv my_venv
/Library/Frameworks/Python.framework/Versions/3.4/bin/python3.4: No module named venv
$ pyvenv tester
File "/Library/Frameworks/Python.framework/Versions/3.4/bin/pyvenv", line 10
print('Error: %s' % e, file=sys.stderr)
^
SyntaxError: invalid syntax