With PHP you have the phpinfo()
which lists installed modules and then from there look up what they do.
Is there a way to see what packages/modules are installed to import?
Type help()
in the interpreter
then
To get a list of available modules, keywords, or topics, type "modules",
"keywords", or "topics". Each module also comes with a one-line summary
of what it does; to list the modules whose summaries contain a given word
such as "spam", type "modules spam".
help> modules