build tree from dotted strings

tree.py

#! /usr/bin/python

a = [
        'uno.due',
        'uno.tre',
        'uno.due.quattro'
]

root = {'uno': {}}

for it in a:
        data = it.split(".")

        cur = root

        for part in data:
                if part in cur:
                        cur = cur[part]
                else:
                        cur[part] = {}
                        cur = cur[part]

print root