urllib package: modules not included

Question

I've imported the urllib package but it doesn't seem to come with its modules out of the box like I was used to expect.

>>> import urllib
>>> dir(urllib.request) 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: module 'urllib' has no attribute 'request'

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

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

The docs describe urllib as "a package that collects several modules for working with URLs". Does it mean anything particularly?
I mean, usually packages when imported fully (import package) deliver "the whole package".
So, is urllib a particular type of package in that sense, i.e. is there a way to know when to expect this kind of behavior?