在词典词典中总结值

Question

I got something like this:

> d1 = {'System tests': {'failed': 5, 'passed': 0, 'total': 5},
       'Func tests': {'failed': 5, 'passed': 0, 'total': 5}}

> d2 = {'System tests': {'failed': 1, 'passed': 1, 'total': 2}, 
        'Func tests': {'failed': 3, 'passed': 2, 'total': 5}}

> d3 = {'System tests': {'failed': 0, 'passed': 0, 'total': 0}, 
        'Func tests': {'failed': 1, 'passed': 0, 'total': 1}}

I would like to sum values 'failed', passed and total into one dictionary

so the output should be like this:

d4 = {'System tests': {'failed': 6, 'passed': 1, 'total': 7}, 
       'Func tests': {'failed': 9, 'passed': 2, 'total': 11}

What is the easiest solution to do such thing?

I can use basic libraries, except collections.

The solution must be generic, for example if some other dictionaries would appear in the future

Answer 1

input:

d1 = {'a': 100, 'b': 200, 'c':300}
d2 = {'a': 300, 'b': 200, 'd':400}
d = {k : d1.get(k, 0) + d2.get(k,0) for k in set(d1.keys()) | set(d2.keys())}

Output:

{'a': 400, 'b': 400, 'c': 300, 'd': 400}

Answer 2

Using Counter and defaultdict that is fairly straight forward like:

Code:

d4 = defaultdict(Counter)
for d in d1, d2, d3:
    for k, subd in d.items():
        d4[k].update(subd)

Test Code:

d1 = {'System tests': {'failed': 5, 'passed': 0, 'total': 5},
        'Func tests': {'failed': 5, 'passed': 0, 'total': 5}}

d2 = {'System tests': {'failed': 1, 'passed': 1, 'total': 2},
        'Func tests': {'failed': 3, 'passed': 2, 'total': 5}}

d3 = {'System tests': {'failed': 0, 'passed': 0, 'total': 0},
        'Func tests': {'failed': 1, 'passed': 0, 'total': 1}}

from collections import Counter, defaultdict

d4 = defaultdict(Counter)
for d in d1, d2, d3:
    for k, subd in d.items():
        d4[k].update(subd)
print(d4)

Results:

defaultdict(<class 'collections.Counter'>, {
    'System tests': Counter({'total': 7, 'failed': 6, 'passed': 1}), 
    'Func tests': Counter({'total': 11, 'failed': 9, 'passed': 2})
})

Answer 3

This will give you the output you are looking for, with no libraries.

d4 = {}

for d in d1, d2, d3:
    for test, results in d.items():
        if test not in d4:
            d4[test] = {}
        for key, value in results.items():
            if key in d4[test]:
                d4[test][key] += value
            else:
                d4[test][key] = value

Result:

{'System tests': {'failed': 6, 'passed': 1, 'total': 7}, 'Func tests': {'failed': 9, 'passed': 2, 'total': 11}}

Answer 4

If you cannot use collections.Counter , another solution is to use reduce

from functools import reduce # reduce was moved here in Python3

def add_dicts(dict_list):

    def add(fst, snd):
        return {k: fst[k] + snd[k] for k in fst}

    return reduce(add, dict_list[1:], dict_list[0])

Using this in your code would look like this.

dict_list = [d1, d2, d3]

d4 = {}

for k in dict_list[0]:
    d4[k] = add_dicts([d[k] for d in dict_list])

Although, this assumes all your dict are correctly formated.

Answer 5

You can use zip along with dict.items :

d1 = {'System tests': {'failed': 5, 'passed': 0, 'total': 5},
   'Func tests': {'failed': 5, 'passed': 0, 'total': 5}}
d2 = {'System tests': {'failed': 1, 'passed': 1, 'total': 2}, 
    'Func tests': {'failed': 3, 'passed': 2, 'total': 5}}
d3 = {'System tests': {'failed': 0, 'passed': 0, 'total': 0}, 
    'Func tests': {'failed': 1, 'passed': 0, 'total': 1}}

def combine_dicts(*d):
   return {a:{i:sum(h[i] for h in [b, c, d]) for i in ['failed', 'passed', 'total']} for [a, b], [_, c], [_, d] in zip(*d)}

print(combine_dicts(d1.items(), d2.items(), d3.items()))

Output:

{'System tests': {'failed': 6, 'total': 7, 'passed': 1}, 'Func tests': {'failed': 9, 'total': 11, 'passed': 2}}