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

Yet another solution:

a = {"A":3, "B":2, "C":6}
b = {"B":7, "C":4, "D":1}

Two liner:

b.update({k:max(a[k],b[k]) for k in a if b.get(k,'')})
res = {**a, **b}

Or if you don't want to change b:

b_copy = dict(b)
b_copy.update({k:max(a[k],b[k]) for k in a if b.get(k,'')})
res = {**a, **b_copy}

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