Get the path to the Python executable associated with the instance currently
being used by reticulate.
py_exe()The path to the associated Python executable, or NULL if Python
has not yet been initialized.
This can occasionally be useful if you'd like to interact with Python (or its
modules) via a subprocess; for example you might choose to install a package
with pip:
system2(py_exe(), c("-m", "pip", "install", "numpy"))
and so you can also have greater control over how these modules are invoked.