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To remove a virtual environment, deactivate it and remove the directory:

(.venv) $ deactivate
$ rm -rf .venv

The venv module has more options, which can be shown with the -h flag:

$ python3 -m venv -h
usage: venv [-h] [--system-site-packages] [--symlinks | --copies] [--clear]
 [--upgrade] [--without-pip] [--prompt PROMPT]
 ENV_DIR [ENV_DIR ...]
Creates virtual Python environments in one or more target directories.
positional arguments:
 ENV_DIR A directory to create the environment in.

optional arguments:
 -h, --help show this help message and exit
 --system-site-packages
 Give the virtual environment access to the system
 site-packages dir.
 --symlinks Try to use symlinks rather than copies, when symlinks
 are not the default for the platform.
 --copies Try to use copies rather than symlinks, even when
 symlinks are the default for the platform.
 --clear Delete the contents of the environment directory if it
 already exists, before environment creation.
 --upgrade Upgrade the environment directory to use this version
 of Python, assuming Python has been upgraded in-place.
 --without-pip Skips installing or upgrading pip in the virtual
 environment (pip is bootstrapped by default)
 --prompt PROMPT Provides an alternative prompt prefix for this
 environment.
Once an environment has been created, you may wish to activate it, for example, by
sourcing an activate script in its bin directory.

A convenient way of dealing with virtual environments, especially if you often have to swap between them, is using the  virtualenvwrapper module:

1. To install it, run this:

$ pip install virtualenvwrapper

2. Then, add the following variables to your sheet startup script, these normally being .bashrc or .bash_profile. The virtual environments will be installed under the WORKON_HOME directory instead of the same directory as the project, as shown previously:

export WORKON_HOME=~/.virtualenvs
source /usr/local/bin/virtualenvwrapper.sh

Sourcing the startup script or opening a new Terminal will allow you to create new virtual environments:

$ mkvirtualenv automation_cookbook
...
Installing setuptools, pip, wheel...done.
(automation_cookbook) $ deactivate
$ workon automation_cookbook
(automation_cookbook) $

For more information, check the documentation of virtualenvwrapper at: https://virtualenvwrapper.readthedocs.io/en/latest/index.html.