condawrapper

A set of wrappers for activating and deactivating conda environments, inspired by virtualenvwrapper.

Installation

Source the condawrapper.sh script:

$ source condawrapper.sh

Usage

Several commands are provided: activate, deactivate, mkcondaenv and rmcondaenv. The activate command will activate the specified conda environment:

$ activate my-env-name

The deactivate command deactivates the currently active conda environment:

$ deactivate

The mkcondaenv command will create a new conda environment with a given name. Remaining arguments are passed to the conda create command, and at least one package specification must be provided. For example, to create an environment containing just Python 2:

$ mkcondaenv my-env-name python=2

Any conda create options may be passed to mkcondaenv after the name of the environment:

$ mkcondaenv my-env-name -c channel -y python=2 [package_spec...]

The mkcondaenv command will automatically create the environment and a condawrapper configuration directory for the environment.

A complementary rmcondaenv command is also provided. Its function is to completely remove a conda environment, including the configuration directory and all its contents:

$ rmcondaenv my-env-name

Environment hooks

The main reason for providing the wrapper is to allow the definition of arbitrary hooks to be run when activating/deactivating an environment. Four hooks are defined: preactivate, postactivate, predeactivate and postdeactivate. The preactivate hook is run before the environment is activated, and the postactivate hook is run after the environment is activated. The deactivation hooks work analgously.

Hooks are just shell scripts that are sourced into the active shell, and are specific to each environment. The default location for hooks is:

$HOME/.condawrapper/<environment-name>

This can be changed by setting the variable CONDAWRAPPER_HOME, e.g.:

$ CONDAWRAPPER_HOME=$HOME/path/to/condawrapper

which results in condawrapper looking for hooks in:

$HOME/path/to/condawrapper/<environment-name>

Example usage

I have a conda environment named work, and when I load this environment I want to set an environment variable called DATA_DIR. Assuming I have already sourced the condawrapper.sh script (in my ~/.bashrc most likely) I first need to create a hooks directory for the work environment:

$ mkdir $CONDAWRAPPER_HOME/work

Now I can define my hooks. I want to set a variable named DATA_DIR, and in this case it doesn't matter if this happens before or after the environment is activated, so I'll just use the `postactivate hook:

$ echo "export DATA_DIR='/path/to/data'" >> $CONDAWRAPPER_HOME/work/postactivate

Now when I activate the work environment the DATA_DIR variable will be set. I also want to make sure I clean up after the environment is deactivated, so I will create a second hook to unset the DATA_DIR variable when the environment is deactivated:

$ echo "unset DATA_DIR" >> $CONDAWRAPPER_HOME/work/predeactivate

Now when the work environment is deactivated the environment variable DATA_DIR is un-set:

    $ echo $DATA_DIR
    
    $ activate work
    $ echo $DATA_DIR
    /path/to/data
    $ deactivate
    $ echo $DATA_DIR
    

Tab completion

The activate and rmcondaenv commands support tab completion in bash, you just need to source the file condawrapper_completion.bash in your shell:

source condawrapper_completion.bash

Problems/suggestions

Please use the Github issue tracker to report issues or suggest imporvements. Pull requests welcome.

License

Released under an MIT style license.