Skip to content
hero
Philippe Bordron

Modify a conda environment

Commands conda install and conda remove are available for this purpose

Additional resources

How to add a package?

This can be done by using the conda install <pkg1> <pkg2> ... command.

Example

# We activate the environment where to install the packagesource activate <env># We install the packageconda install python...

How to install or to update a package to a specific version?

You can use the notations =, ==, !=, <=, <, >= and > to target a package version.

Examples

  • Install the last python 2 version in an existing environment:

    # We activate the environment where we want to add package(s)source activate <env># We install the last python before the version 3 (i.e. python 2.x.y)conda install "python<3"...# We check the python versionconda list# packages in environment at <env>:# # Name Version Build Channel...
    python 2.7.15 h5a48372_1011_cpython conda-forge
    ...

  • Install numpy between version 1.22.0 included and 1.22.3 excluded:

    source activate <env>conda install "numpy>=1.22,<1.22.3"...conda list# packages in environment at <env>:# # Name Version Build Channel...
    numpy 1.22.2 py310h454958d_0 conda-forge
    ...

Danger

Be sure to use " when using > and <.

How to uninstall a package?

You must use the command conda remove:

source activate <env>conda remove <pkg1> <pkg2>

How to use a specific channel?

Sometime, a package is available in a channel you haven't configured. You can use option -c or --channel to install it without altering your conda configuration.

Conda create

This option can also be used with the conda create command.

conda install -p <env_name> -c <channel1> -c <channel2> \ <pkg1> <pkg2> ...

Example

Install DESeq2 from bioconda channel and R, its dependency provided by conda-forge channel.

source activate <env>conda install -c conda-forge -c bioconda bioconductor-deseq2

Channel priority

The further to the left of the command the channel appears, the lower its priority: conda-forge channel has priority over bioconda if a package exists in both channels.