help('modules')Result:
__main__ gc uasyncio/funcs uos
_boot machine uasyncio/lock urandom
_onewire math uasyncio/stream ure
_rp2 micropython ubinascii uselect
_thread onewire ucollections ustruct
_uasyncio rp2 uctypes usys
builtins uasyncio/__init__ uhashlib utime
ds18x20 uasyncio/core uio uzlib
framebuf uasyncio/event ujson
Plus any modules on the filesystem