return the full path of 'python' executable if found.
python_exec()
executable full path in a character vector of length 1.
Other executable full path:
chrome_exec()
,
excel_exec()
,
firefox_exec()
,
libreoffice_exec()
,
node_exec()
,
npm_exec()
,
pip_exec()
,
powerpoint_exec()
,
word_exec()
if(exec_available("python"))
message(python_exec())
#> /opt/python/3.12.4/bin/python3