RDF/XML Fini, and Python - slide "Modules"

Modules are collections of Python objects (classes, functions, etc.) and a namespace
Modules can be nested
Every python file can be treated as a module, with the module name being the same as the file's name
- Imagine the file named 'pytest.py' containing:
```
def square(x):
    return x*x
```
- We can treat that as a module, or just a collection of objects (with no namesapce):
```
>>> import pytest
>>> square(2)
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
>>> execfile('pytest.py')
>>> square(2)
4
>>> pytest.square
<function square at 0x3aceb0>
>>> sq = pytest.square
>>> sq(4)
16
```
- 'rdflib' is the top of the rdflib hierarchy. rdflib has a lot of submodules which have the same name as the principle class in that module
- Key simplifying trick, use sensible import statements:
  - import rdflib.TripleStore imports the module but nothing in the module. So to reference anything in the module, you must go through it.
  - You can always bind that item to a local name, e.g., TripleStore = rdflib.TripleStore.TripleStore
  - from rdflib.TripleStore import TripleStore is sugar for the above trick
  - Avoid from foo import *
  - This will lead to some obvious rdflib boilerplate
- Work through the example