Reverting (key, value) pairs in a dictionary

[Shu-Hsien Sheu]

Hi,

How do you turn a dictionary of <original_key>: <original_value> into 
<original_value>: <original_key>, when there is no duplicate values?
For instance, I have a dictionary kk:
kk = {'abc': ['B', 'C', 'D', 'E'], 'def':['G', 'H']}

and I want a new dictionary newkk which looks like:
newkk = {'B':'abc', 'C':'abc', 'D':'abc', 'E':'abc', 'G':'def', 'H':'def'}

My codes are:

 >>> kk = {'abc': ['B', 'C', 'D', 'E'], 'def':['G', 'H']}
 >>> new = []
 >>> for i, item in kk.items():
    for j in item:
        new.append([j, i])
 >>> newkk = dict(new)
 >>> new
[['B', 'abc'], ['C', 'abc'], ['D', 'abc'], ['E', 'abc'], ['G', 'def'], 
['H', 'def']]
 >>> newkk
{'C': 'abc', 'B': 'abc', 'E': 'abc', 'D': 'abc', 'G': 'def', 'H': 'def'}

Is there a better way of doing it?

-shuhsien