Miniforge: conda, mamba and conda-forge

In this page, we give indications about how to install Miniforge and use conda/mamba. Please, if you encounter problems, fill an issue here to explain what you did and what are the errors (please copy / paste the error log).

The first step is to install Miniforge, which is a modified version of Miniconda using by default the community driven conda-forge channel.

Windows

On Windows, download the Windows installer and follow the instructions given in conda-forge/miniforge.

Open an Anaconda Prompt and run conda init --all.

Unix (Linux and macOS)

Download the installer using curl or wget or your favorite program. For eg:

wget "https://github.com/conda-forge/miniforge/releases/latest/download/Miniforge3-$(uname)-$(uname -m).sh"

or

curl -L -O "https://github.com/conda-forge/miniforge/releases/latest/download/Miniforge3-$(uname)-$(uname -m).sh"

Execute the installer and initialize conda:

bash Miniforge3-$(uname)-$(uname -m).sh -b
$HOME/miniforge3/bin/conda init --all

When it’s done, open a new terminal (click on ctrl-alt-t) and check that the line in the new terminal starts with (base). The indication (base) means that you use the base “environment”.

However, working in the base environment is not a good practice and it is better to disable the auto activation with:

conda config --set auto_activate_base false

conda and mamba are 2 commandline tools to manage software installations and create “environments”.

conda and mamba: differences?

Conda is an open source package management system and environment management system that runs on Windows, macOS and Linux.

Mamba is a new implementation of conda, which can be faster for some operations. However, modern conda now uses internally some parts of mamba, so one can just use the conda command line.

Definition: environment

A environment is a set of programs and libraries with particular versions. An environment is defined by the software installed on your computer and by environment variables, in particular the variable $PATH, which contains all the paths where your shell looks for programs (you can read the output of echo $PATH).

It is very useful to be able to create different environments for different tasks. It is usually better to keep the base environment only for the conda software and to use different environments for other tasks. We will use this strategy here. We will have

• 1 environment for some basic libraries used in this course (called main),

• 1 environment with Fluidsim and MPI (called env-fluidsim-mpi).

conda takes the programs that it installs from “channels”. We are going to use the largest open-source community driven channel called conda-forge. With Miniforge, conda-forge is by default the main channel.

We can start by creating the main environment with the commands:

conda env create --file https://foss.heptapod.net/fluiddyn/fluidhowto/-/raw/branch/default/book/python/conda-env-main.yml

Content of the .yml file describing the environment?

name: main
dependencies:
  # standard packages
  - ipython
  - numpy
  - matplotlib
  - ipympl
  - scipy
  - pandas
  # jupyterlab and few nice extensions
  - jupyterlab
  - jupyterlab-myst
  - jupyterlab-spellchecker
  - jupyterlab-variableInspector
  # to be able to use this environment with Spyder
  - nb_conda_kernels

While conda creates the environment, we can study the most important conda commands:

• conda activate main

• conda deactivate

• conda search fluidsim

• conda create -n name-env numpy pandas

• conda env list

Tip

One can add the line conda activate main at the end of the file ~/.bashrc.