Steven, Thank you for your reply and question. > > What should the result be if both dictionaries have the same key? The answer: the values should be added together and assigned to the key That is {'a':1, 'b':5} ( from your example below)
Is there a solution? Thanks for the reply L. > > a={'a':1, 'b'=2} > b={'b':3} > > should the result be: > {'a':1, 'b'=2} # keep the existing value > {'a':1, 'b'=3} # replace the existing value > {'a':1, 'b'=[2, 3]} # keep both values > or something else? > > Other people have already suggested using the update() method. If you want > more control, you can do something like this: > > def add_dict(A, B): > """Add dictionaries A and B and return a new dictionary.""" > C = A.copy() # start with a copy of A > for key, value in B.items(): > if C.has_key(key): > raise ValueError("duplicate key '%s' detected!" % key) > C[key] = value > return C > > > -- > Steven. -- http://mail.python.org/mailman/listinfo/python-list