To merge two dictionaries of list in Python

Question

There are two dictionaries

x={1:[\'a\',\'b\',\'c\']}
y={1:[\'d\',\'e\',\'f\'],2:[\'g\']}

I want another dictionary z which is a merged one

Answer 1

One line solution:

{ key:x.get(key,[])+y.get(key,[]) for key in set(list(x.keys())+list(y.keys())) }

Example 1:

x={1:['a','b','c']}
y={1:['d','e','f'],2:['g']}
{ key:x.get(key,[])+y.get(key,[]) for key in set(list(x.keys())+list(y.keys())) }

Output:

{1: ['a', 'b', 'c', 'd', 'e', 'f'], 2: ['g']}

Example 2:

one = {'a': [1, 2], 'c': [5, 6], 'b': [3, 4]}
two = {'a': [2.4, 3.4], 'c': [5.6, 7.6], 'd': [3.5, 4.5]}
{ key:one.get(key,[])+two.get(key,[]) for key in set(list(one.keys())+list(two.keys())) }

Output:

{'a': [1, 2, 2.4, 3.4], 'b': [3, 4], 'c': [5, 6, 5.6, 7.6], 'd': [3.5, 4.5]}