Why can the IPython shell find urllib.parse while the simple python shell cannot?

Question

I am having trouble understanding the following behavior using Python 3.4.3:

In [1]: import urllib

In [3]: urllib.parse
Out[3]: <module 'urllib.parse' from '/home/laurent/anaconda/envs/springleaf/lib/python3.4/urllib/parse.py'>

In [4]: urllib.request
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-4-615cd424e6d8> in <module>()
----> 1 urllib.request

AttributeError: 'module' object has no attribute 'request'

I looked at urllib's package [myenv]/lib/python3.4/urllib, but its just empty __init__.py, and I can’t understand why the submodule parsewill be visible until the submodule requestor errornot.
The behavior I was expecting was to make all modules visible.

What causes a module to be visible parsewhile other modules are not?

I can use it from urllib import requestjust fine, but I would like to understand the reason for the behavior.

EDIT: As recommended in the comments, I ran the same commands in a simple python shell (I used IPython 4.0.0 above):

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

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, - , IPython;).