Create Python Virtual Environment

I attempted to install MkDocs on one of my Linux computers. I ran into an issue where it would display the below message.

almostengr@peppermint:~$ python3 -m pip install mkdocs
error: externally-managed-environment

× This environment is externally managed
╰─> To install Python packages system-wide, try apt install
    python3-xyz, where xyz is the package you are trying to
    install.

    If you wish to install a non-Debian-packaged Python package,
    create a virtual environment using python3 -m venv path/to/venv.
    Then use path/to/venv/bin/python and path/to/venv/bin/pip. Make
    sure you have python3-full installed.

    If you wish to install a non-Debian packaged Python application,
    it may be easiest to use pipx install xyz, which will manage a
    virtual environment for you. Make sure you have pipx installed.

    See /usr/share/doc/python3.12/README.venv for more information.

note: If you believe this is a mistake, please contact your Python installation or OS distribution provider. You can override this, at the risk of breaking your Python installation or OS, by passing --break-system-packages.
hint: See PEP 668 for the detailed specification.

Not sure what this message meant, I followed the instructions that were provided. Below is what happened.

almostengr@peppermint:~$ sudo apt install python3-mkdocs
 [sudo] password for almostengr:                
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
E: Unable to locate package python3-mkdocs

The above was not surprising, but also slightly irritating. Did what it suggested and it still did not work.

almostengr@peppermint:~$ python3 -m venv python
The virtual environment was not created successfully because ensurepip is not
available.  On Debian/Ubuntu systems, you need to install the python3-venv
package using the following command.

    apt install python3.12-venv

You may need to use sudo with that command.  After installing the python3-venv
package, recreate your virtual environment.

Failing command: /home/almostengr/python/bin/python3

almostengr@peppermint:~$ sudo apt install python3-venv 
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following additional packages will be installed:
  python3-pip-whl python3-setuptools-whl python3.12-venv
The following NEW packages will be installed:
  python3-pip-whl python3-setuptools-whl python3-venv python3.12-venv
0 upgraded, 4 newly installed, 0 to remove and 1 not upgraded.
Need to get 2,430 kB of archives.
After this operation, 2,783 kB of additional disk space will be used.
Do you want to continue? [Y/n] 

Installation completed succesfully. Tried running the same command again to install MkDocs, but ran into an error. Did some research and found that I need to source the activate file within the bin directory of the virtual environment.

almostengr@peppermint:~/python$ ls 
bin  include  lib  lib64  pyvenv.cfg
almostengr@peppermint:~/python$ cd bin/
almostengr@peppermint:~/python/bin$  ls 
activate  activate.csh  activate.fish  Activate.ps1  pip  pip3  pip3.12  python  python3  python3.12
almostengr@peppermint:~/python/bin$ source activate
(python) almostengr@peppermint:~/python/bin$ pip3 install mkdocs 

After doing all of that, the command finally works.

(python) almostengr@peppermint:~/python/bin$ mkdocs 
Usage: mkdocs [OPTIONS] COMMAND [ARGS]...

  MkDocs - Project documentation with Markdown.

Options:
  -V, --version         Show the version and exit.
  -q, --quiet           Silence warnings
  -v, --verbose         Enable verbose output
  --color / --no-color  Force enable or disable color and wrapping for the output. Default is auto-detect.
  -h, --help            Show this message and exit.

Commands:
  build      Build the MkDocs documentation.
  get-deps   Show required PyPI packages inferred from plugins in mkdocs.yml.
  gh-deploy  Deploy your documentation to GitHub Pages.
  new        Create a new MkDocs project.
  serve      Run the builtin development server.

Now to prevent having to source the Python virtual environment, I updated the .bashrc file to include the below.

alias mkdocs='/home/almostengr/python/bin/mkdocs'

This will call the mkdocs files that have been loaded onto the computer each time.