Conda environments

README.md

How to manage Conda

In the example below we will install two same Python's versions side by side, but for the different architectures. When to use Conda? When you've been using pre-built Python packages. If you use pip or wheel packages a lot it is better to stick to vanilla Python distribution. That's it.

Preload Conda

Make sure you have the following either in ~/.bashrc or in ~/.bash_profile files defined

eval "$(/c/tools/miniconda/Scripts/conda shell.posix hook)"

or

source /c/tools/miniconda/etc/profile.d/conda.sh

or

# this will load base profile no matter what settings you have
source /c/tools/miniconda/Scripts/activate

To add Conda hook to Windows command-prompt (this will also enable UTF-8 charset)

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\SOFTWARE\Microsoft\Command Processor]
"Autorun"="@chcp 65001>nul & call \"C:\\Tools\\miniconda\\condabin\\conda_hook.bat\""

To add Conda hook to Windows PowerShell

if (!(Test-Path -Path $PROFILE )) { New-Item -Type File -Path $PROFILE -Force }
$CondaHook = @'
& C:\Tools\miniconda\shell\condabin\conda-hook.ps1
'@
Add-Content -Path $PROFILE -Value $CondaHook

Ad-hoc run Windows PowerShell

powershell.exe -NoExit -ExecutionPolicy Bypass -Command "& C:\Tools\miniconda\shell\condabin\conda-hook.ps1"

To run Conda on Cygwin create new environment variable SHELLOPTS and set its value to igncr, then restart your shell.

rundll32.exe sysdm.cpl,EditEnvironmentVariables

Python

1. Base configuration

   conda update -n base -c defaults conda
   conda config --set changeps1 false
   conda config --set auto_activate_base false # same as export CONDA_AUTO_ACTIVATE_BASE="false"
   conda config --set auto_update_conda false

2. Create Python 3.6 x86 environment

   conda create -n python36_x86
   conda activate python36_x86
   conda config --env --set subdir win-32
   conda install python=3.6
   # alternative
   conda create -n python36_x86
   conda install -n python36_x86 -c defaults/win-32 --override-channels python=3.6
   # alternative
   conda create -n python36_x86 -c defaults/win-32 --override-channels python=3.6
   # now activate
   conda activate python36_x86

   # alternative
   conda env create --prefix ./envs -c defaults/win-32 --override-channels python=3.6
   conda activate ./envs

3. Create Python 3.6 x64 environment

   conda create -n python36_x64
   conda activate python36_x64
   conda config --env --set subdir win-64
   conda install python=3.6
   # alternative
   conda create -n python36_x64
   conda install -n python36_x64 -c defaults/win-64 --override-channels python=3.6
   # alternative
   conda create -n python36_x64 -c defaults/win-64 --override-channels python=3.6
   # now activate
   conda activate python36_x64

   # alternative
   conda env create --prefix ./envs -c defaults/win-64 --override-channels python=3.6
   conda activate ./envs

4. Manage packages

   # list packages
   conda list -n python36_x64
   conda list
   # search packages
   conda search requests
   conda search --channel defaults/win-64 --override-channels requests
   # install packages
   conda install --name python36_x64 requests
   conda install requests
   conda install -c conda-forge/win-64 --override-channels awscli boto3
   # update packages
   conda update conda
   conda update anaconda
   conda update python
   # remove packages
   conda remove -n python36_x64 requests
   conda remove requests

   # configure new environments to install packages by default
   conda config --add create_default_packages awscli
   # override with --no-default-packages flag
   conda create -n python36_x64 -c defaults/win-64 --override-channels --no-default-packages python=3.6

5. Update all

   conda update --all --yes
   # except python
   conda install python=3.6.10

6. Delete environment if not needed

   conda env remove -n python36_x86 -y
   # alternative
   conda remove -n python36_x86 --all -y

7. Prepared environment definition

   # create & delete
   conda env export -n python36_x64 -c defaults/win-64 --override-channels > environment.yml
   # same as previous
   conda env export -n python36_x64 -c defaults/win-64 --override-channels -f environment.yml
   # now remove
   conda remove -n python36_x64 --all -y

   # restore
   conda env create -f environment.yml -n python36_x64 -p ./envs

   # update
   conda env update -n python36_x64 --file environment.yml --prune

Additional info

https://docs.conda.io/projects/conda/en/latest/user-guide/tasks/manage-environments.html

https://docs.conda.io/projects/conda/en/latest/user-guide/tasks/manage-pkgs.html

https://conda.io/projects/conda/en/latest/user-guide/configuration/use-condarc.html

https://docs.conda.io/projects/conda/en/latest/configuration.html

activate.sh

###############################################################################

#  Anaconda Environment Selection - Plese set CONDA_BASE_DIR to the directory
#  containing the base installation of anaconda/miniconda.
#
#  Append to .bash_profile like so: source "${HOME}/.config/conda/activate.sh"
#
#  For cygwin only

export CONDA_BASE_DIR="/cygdrive/c/tools/miniconda"

#  Proxy Servers & Network Setup (if needed)

export HTTP_PROXY=
export HTTPS_PROXY=

#  IMPORTANT - Ignore carriage returns when using a Cygwin environment.

export SHELLOPTS
set -o igncr

###############################################################################

#  Manage conda environments for Python.  We check the environment variable
#  $CONDA_DEFAULT_ENV to see which environment is desired.  The default (base)
#  environment will be chosen if nothing is specified.  Note that this variable
#  will be explicitly managed by the cyg-activate ( ) function we have defined
#  below, specifically for the purpose of changing environments.  The base
#  environment is also handled slightly different from the others when it comes
#  to setting the CONDA_DEFAULT_ENV variable.

if [ "${CONDA_DEFAULT_ENV}" ] && [ "${CONDA_DEFAULT_ENV}" != 'base' ]; then
    #  SELECT ONE OF THE NON-DEFAULT ENVIRONMENTS
    export CONDA_PREFIX="${CONDA_BASE_DIR}/envs/${CONDA_DEFAULT_ENV}"
else
    #  SELECT THE DEFAULT ENVIRONMENT (and set CONDA_DEFAULT_ENV full path)
    export CONDA_DEFAULT_ENV='base'
    export CONDA_PREFIX="${CONDA_BASE_DIR}"
fi

###############################################################################

#  Define cyg-conda and cyg-activate to facilitate management of conda.

alias cyg-conda="${CONDA_BASE_DIR}/Scripts/conda.exe"

cyg-activate() {
    export CONDA_DEFAULT_ENV="$1"
    source "${HOME}/.bash_profile"
    cyg-conda info --envs
}

###############################################################################

#  PATH - ALl of the anaconda/miniconda path entries appear first.

PATH=
PATH="${PATH}:${CONDA_PREFIX}"
PATH="${PATH}:${CONDA_PREFIX}/Library/mingw-w64/bin"
PATH="${PATH}:${CONDA_PREFIX}/Library/usr/bin"
PATH="${PATH}:${CONDA_PREFIX}/Library/bin"
PATH="${PATH}:${CONDA_PREFIX}/Scripts"
PATH="${PATH}:${HOME}/scripts"
PATH="${PATH}:${HOME}/local/bin"
PATH="${PATH}:/usr/local/bin"
PATH="${PATH}:/usr/bin"

export PATH

###############################################################################