Why does importing a python module not import nested modules?

Question

If I do this:

import lxml 

in python, lxml.html is not imported. For instance, I cannot call the lxml.html.parse()

Answer 1

lxml is called a package in Python, which is a hierachical collections of modules. Packages can be huge, so they are allowed to be selective about what is pulled in when they are imported. Otherwise everybody would have to import the full hierarchy, which would be quite a waste of resources.