A very simple script to realize the basic DS combination rules with just 10 lines codes
The input is 2 Diction sets, the keys can be number or strings, whatever you like. for example
a={1:0.5, 12:0.5}
b={1:0.3, 2:0.6, 12:0.1}
DSCombination(a,b)
The results would be
{1: 0.5, 2: 0.4285714285714286, 12: 0.071428571428571438}
or use keys with strings
a={'a':0.5, 'ab':0.5}
b={'b':0.3, 'abc':0.6, 'c':0.1}
DSCombination(a,b)
The results would be
{'a': 0.39999999999999997,
'ab': 0.39999999999999997,
'abc': 0.0,
'b': 0.19999999999999998,
'c': 0.0}
Following editions will consider the situation of confliction.