On Wed, 18 Oct 2006 08:24:27 -0700, Lad wrote: > How can I add two dictionaries into one? > E.g. > a={'a:1} > b={'b':2} > > I need > > the result {'a':1,'b':2}. > > Is it possible?
What should the result be if both dictionaries have the same key? 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