question about shadowing built-in names

[John Salerno]

I understand that if you reassign a built-in name to your own variable, 
such as:

str = 'hello'

then you lose the use of the built-in (in this case str()), but is this 
also the case in terms of imported names? For example:

import MySQLdb

db = connect(blah blooh blee)
cursor = db.cursor()

Now, in the above, did I reassign the value of the cursor method, or is 
this different?

Actually, now that I think about it, that's not exactly the same because 
cursor is a method of a connection object, not simply a function. So I 
suppose my real question is, does the 'shadowing' of built-in names also 
  happen when you import other names, whether they are functions, 
methods or whatever else they could be?

Thanks.