获取字典中的值之和

Question

I have a dictionary where key is a country name and value is a list of two or 1 numbers. I need to get the sum of those two values in a form of a dictionary where key is the country and the value is the sum.

I've tried using sum() but I get an error that states - can only concatenate list (not "int") to list.

country_home = sorted(Counter(data['home_team']).most_common()) # gives back ('America', 18)
country_away = sorted(Counter(data['away_team']).most_common()) # gives back ('America', 10)

        country_away = sorted(Counter(data['away_team']).most_common())
        d = defaultdict(list)
        for a, b in country_home + country_away:
            d[a].append(b)
        print(d) # gives back {'America': [18, 10], 'Canada': [37, 65], 'Mexico: [10], ...}

The expected result is a list or a dictionary

{'America': [28], 'Canada': [102], ... }

Answer 1

Why don't you just do:

Counter(data['home_team'] + data['away_team']).most_common()

Example:

from collections import Counter, OrderedDict
data = {
    'home_team': 'America America  America  America America America Canada'.split(),
    'away_team': 'America America  America  America America America Canada'.split()
}

print(OrderedDict(Counter(data['home_team'] + data['away_team']).most_common()))

Output :

OrderedDict([('America', 12), ('Canada', 2)])

If you don't care about order use dict(..) instead of OrderedDict(..)

Or you can do this:

  print(dict((Counter(data['home_team'])+ Counter(data['away_team'])).most_common()))

Answer 2

Without harming the original dictionary you can try:

a = {'America':[18,20],'Canada':[37,65],'c':[4,5,6]}
b = {x:a[x] for x in a}
b = {x : [] for x in b}
for i in a:
    b[i].append(sum(a[i]))
print(b)

Output:

{'America': [38], 'Canada': [102], 'c': [15]}

This way whenever a new key is added to the first dictionary, it will be added to diciontary b .

Answer 3

With minimal changes to your code, following should work.

     country_away = sorted(Counter(data['away_team']).most_common())
        d = defaultdict(list)
        for a, b in country_home + country_away:
            d[a].append(b)
            d[a] = [sum(d[a])] # sum up the list
        print(d) # should give back {'America': [28], 'Canada': [102], 'Mexico': [10]...}

Is this what you wanted to do?

Cheers

Answer 4

You can process the dictionary using dict comprehension

d = {'America':[18,20],'Canada':[37,65],'c':[4,5,6]}
res = {k:[sum(v)] for k,v in d.items()}
print(res)

Output:

{'America': [38], 'Canada': [102], 'c': [15]}