conda / Conda

Conda is a cross-platform, language-agnostic binary package manager. It is the package manager used by Anaconda installations, but it may be used for other systems as well. Conda makes environments first-class citizens, making it easy to create independent environments even for C libraries. Conda is written entirely in Python, and is BSD licensed open source.

Conda is enhanced by organizations, tools, and repositories created and managed by the amazing members of the conda community. Some of them can be found here.

Installation

Conda is a part of the Anaconda Distribution. Use Miniconda to bootstrap a minimal installation that only includes conda and its dependencies.

Getting Started

If you install Anaconda, you will already have hundreds of packages installed. You can see what packages are installed by running

$ conda list

to see all the packages that are available, use

$ conda search

and to install a package, use

$ conda install <package-name>

The real power of conda comes from its ability to manage environments. In conda, an environment can be thought of as a completely separate installation. Conda installs packages into environments efficiently using hard links by default when it is possible, so environments are space efficient, and take seconds to create.

The default environment, which conda itself is installed into is called base. To create another environment, use the conda create command. For instance, to create an environment with the IPython notebook and NumPy 1.6, which is older than the version that comes with Anaconda by default, you would run

$ conda create -n numpy16 ipython-notebook numpy=1.6

This creates an environment called numpy16 with the latest version of the IPython notebook, NumPy 1.6, and their dependencies.

We can now activate this environment, use

# On Linux and Mac OS X
$ source activate numpy16

# On Windows
> activate numpy16

This puts the bin directory of the numpy16 environment in the front of the PATH, and sets it as the default environment for all subsequent conda commands.

To go back to the base environment, use

# On Linux and Mac OS X
$ source deactivate

# On Windows
> deactivate

Building Your Own Packages

You can easily build your own packages for conda, and upload them to anaconda.org, a free service for hosting packages for conda, as well as other package managers. To build a package, create a recipe. Package building documentation is available here. See https://github.com/AnacondaRecipes for the recipes that make up the Anaconda Distribution and defaults channel. Conda-forge and Bioconda are community-driven conda-based distributions.

To upload to anaconda.org, create an account. Then, install the anaconda-client and login

$ conda install anaconda-client
$ anaconda login

Then, after you build your recipe

$ conda build <recipe-dir>

you will be prompted to upload to anaconda.org.

To add your anaconda.org channel, or the channel of others to conda so that conda install will find and install their packages, run

$ conda config --add channels https://conda.anaconda.org/username

(replacing username with the user name of the person whose channel you want to add).

Getting Help

The documentation for conda is at https://conda.io/en/latest/. You can subscribe to the conda mailing list. The source code and issue tracker for conda are on GitHub.

Contributing

Contributions to conda are welcome. See the contributing documentation for instructions on setting up a development environment.