Combine two dictionaries, concatenate string values?

Question

Related: Is there any pythonic way to combine two dicts (adding values for keys that appear in both)?

I\'d like to merge two string:string dictionaries, and concaten

Answer 1

Can write a generic helper, such as:

a = {'foo':'bar', 'baz':'bazbaz'}
b = {'foo':'baz'}

def concatd(*dicts):
    if not dicts:
        return {} # or should this be None or an exception?
    fst = dicts[0]
    return {k: ''.join(d.get(k, '') for d in dicts) for k in fst}

print concatd(a, b)
# {'foo': 'barbaz', 'baz': 'bazbaz'}

c = {'foo': '**not more foo!**'}
print concatd(a, b, c)
# {'foo': 'barbaz**not more foo!**', 'baz': 'bazbaz'}