questions about dir and import in python -

i have questions python's dir function

>>>import urllib >>>dir(urllib) ['__builtins__', '__cached__', '__doc__', '__file__','__loader__','__name__','__package__', '__path__', '__spec__'] 

and when this

>>>import urllib.request >>>dir(urllib) ['__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__','__package__', '__path__', '__spec__', 'error', 'parse', 'request', 'response'] 

why comes 3 more attributes? why request attribute doesn't in dir(urllib) @ first?

i' appriciate help!

urllib package, whereas in urllib.request, request module inside urllib package.

when import package, not automatically import modules inside package, unless module imported __init__.py package.

but __init__.py of urllib empty (its empty in python 3.4) , , hence when importing urllib not import module urllib.request.