merging two python dicts and keeping the max key, val in the new updated dict

Question

I need a method where I can merge two dicts keeping the max value when one of the keys, value are in both dicts.

dict_a maps \"A\", \"B\", \"C\" to 3, 2, 6

dict_

Answer 1

What about

{
    k:max(
        dict_a.get(k,-float('inf')),
        dict_b.get(k,-float('inf'))
    ) for k in dict_a.keys()|dict_b.keys()
}

which returns

{'A': 3, 'D': 1, 'C': 6, 'B': 7}

---

With

>>> dict_a = {'A':3, 'B':2, 'C':6}
>>> dict_b = {'B':7, 'C':4, 'D':1}