Develop Reference

Get a fresh bash without conda

is there a way to easily switch from conda environments to my system's native python environment? When I have conda activated, and I run bash or exec bash it doesn't seem to work, and when I run python it uses conda's python and it's not using the system python path. The only way I've been able to get this to work is by restarting the terminal entirely. Is there a faster way to do this?
(I've actually removed the conda init block from my ~/.bashrc and I run it manually every time I want to use conda's python.)

You have two options:
Just deactivate the base environment:
(base) $ conda deactivate
$
Configure your conda to not activate the base environment on startup.
(base) $ conda config --set auto_activate_base false
<restart shell>
$
# use the system python
$ python
# to use conda you'll need to activate it first
$ conda activate
(base) $ python

The conda command you're looking for is deactivate.
Suppose you have activated the myproject environment.
$ conda deactivate
Now your environment is base, as seen by which python,
or conda info --envs.
$ conda deactivate
Now you're not using conda at all, and which python shows the system
interpreter, likely /usr/bin/python.

This may be a bit of a hack, but what about adding an alias pointing to the system python before the conda block in .bashrc? Assuming you don't want to use "conda deactivate" and lose the environment completely.
alias syspython=`which python`
# >>> conda initalize >>>
...
You should then be able to use the system python in a conda env like so:
syspython file.py ...

Activate Anaconda virtual environment in Windows 10 - error

I like to create a virtual environment for my python project. For that, I like to activate my created environment. For that I am doing this command-
conda create -n <env_name> python=3.6.* -y #Create environment
conda activate <env_name>
After that, I am getting this error-
PS C:\Users\abrar> conda activate
CommandNotFoundError: Your shell has not been properly configured to use 'conda activate'.
If your shell is Bash or a Bourne variant, enable conda for the current user with
$ echo ". C:\tools\miniconda3/etc/profile.d/conda.sh" >> ~/.bashrc
or, for all users, enable conda with
$ sudo ln -s C:\tools\miniconda3/etc/profile.d/conda.sh /etc/profile.d/conda.sh
The options above will permanently enable the 'conda' command, but they do NOT
put conda's base (root) environment on PATH. To do so, run
$ conda activate
in your terminal, or to put the base environment on PATH permanently, run
$ echo "conda activate" >> ~/.bashrc
Previous to conda 4.4, the recommended way to activate conda was to modify PATH in
your ~/.bashrc file. You should manually remove the line that looks like
export PATH="C:\tools\miniconda3/bin:$PATH"
^^^ The above line should NO LONGER be in your ~/.bashrc file! ^^^
Can anyone please help what I need to do to make my pc able to run conda activate command?
Thanks in advance for helping.

How to install packages from yaml file in Conda

I would like to have one YAML file that could serve to both create virtual environments and (most importantly) as a base for installing packages by conda into the global env. I am trying:
conda install --file ENV.yaml
But it is not working since conda expects pip-like format of the requirements. What command should I execute to install packages from my YAML file globally?

You want the conda-env command instead, specifically
conda env update -n my_env --file ENV.yaml
Read the conda env update --help for details.
If you wish to install this in the base env, then you would use
conda env update -n base --file ENV.yaml
Note that the base env isn't technically "global", but rather just the default env as well as where the conda Python package lives. All envs are isolated unless you are either using the --stack flag during activation to override the isolation or have - contra recommended practice - manually manipulated PATH to include an env.

If your conda env is already activated, use:
conda env update --file environment.yml
Or update a specific environment without activating it:
conda env update --name envname --file environment.yml

Conda: Creating a virtual environment

I'm trying to create a virtual environment. I've followed steps from both Conda and Medium.
Everything works fine until I need to source the new environment:
conda info -e
# conda environments:
#
base * /Users/fwrenn/anaconda3
test_env /Users/fwrenn/anaconda3/envs/test_env
source ~/anaconda3/bin/activate test_env
_CONDA_ROOT=/Users/fwrenn/anaconda3: Command not found.
Badly placed ()'s.
I can't figure out the problem. Searching on here has solutions that say adding lines to your bash_profile file, but I don't work in Bash, only C shell (csh). It looks like it's unable to build the directory path in activate.
My particulars:
OS X
Output of python --version:
Python 3.6.3 :: Anaconda custom (64-bit)
Output of conda --version:
conda 4.4.7

I am not sure what causes the problem in your case, but code below works for me without any issues (OS X, the same version of Conda as yours).
Creation of the environment
conda create -n test_env python=3.6.3 anaconda
Some explanation of the documentation of conda create is not clear:
-n test_env sets name of the environment to test_env
python=3.6.3 anaconda says that you want to use python in version 3.6.3 in this environment (exactly the one you have, and you can use a different one if you need it) and package anaconda. You can put all the things you need there, separated with spaces, e.g., sqlite matplotlib requests and specify their versions the same way as for python.
Activation
conda activate test_env
Deactivation
conda deactivate
Getting rid of it
conda remove -n test_env --all

Check if Conda is installed
conda -V
Check if Conda is up to date
conda update conda
Create a virtual environment
conda create -n yourenvname python=x.x anaconda
Activate your virtual environment
source activate yourenvname
Install additional Python packages to a virtual environment
conda install -n yourenvname [package]
Deactivate your virtual environment
source deactivate
Delete the virtual environment
conda remove -n yourenvname --all

I was able to solve my problem. Executing the source activate test_env command wasn't picking up my .bash_profile, and I normally work in tcsh. Simply starting a subprocess in Bash was enough to get activate working. I guess I assumed, incorrectly, that the activate command would start a child process in Bash and use Bash environment variables.
> conda info -e
> # conda environments:
> #
> base * ~/anaconda3
> test_env ~/anaconda3/envs/test_env
> bash
~$ source ~/anaconda3/bin/activate test_env
(test_env) ~$
(test_env) ~$ conda info -e
# conda environments:
#
test_env * ~/anaconda3/envs/test_env
root ~/anaconda3

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.