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

Extending this so you can have any number of dictionaries in a list rather than just two:

a = {'a': 3, 'b': 2, 'c': 6}
b = {'b': 7, 'c': 4, 'd': 1}
c = {'c': 1, 'd': 5, 'e': 7}

all_dicts = [a,b,c]

from functools import reduce

all_keys = reduce((lambda x,y : x | y),[d.keys() for d in all_dicts])

max_dict = { k : max(d.get(k,0) for d in all_dicts) for k in all_keys }