Like 'calculate-anything', needs simpleeval library:

~$  pipx install simpleeval
No apps associated with package simpleeval or its dependencies. If you are attempting to install a library, pipx should not be used. Consider using pip or a similar tool instead.

~$  pip install simpleeval
error: externally-managed-environment
× This environment is externally managed
╰─> To install Python packages system-wide, try pacman

~$ yay -Ss simpleeval
aur/python-simpleeval 0.9...
    A simple, safe single expression evaluator library.

What to do, install from AUR?