在Python中将字典加在一起

Question

If i have 2 dictionaries x={'a':1,'b':2} and y={'a':1,'b':3}

and i want the output z={'a':2,'b':5} , is there a z=dict.add(x,y) function or should i convert both dictionaries into dataframes and then add them together with z=x.add(y) ?

Answer 1

You could use Counter in this case for example:

from pprint import pprint
from collections import Counter

x={'a':1,'b':2}
y={'a':1,'b':3}

c = Counter()
c.update(x)
c.update(y)

pprint(dict(c))

Output:

{'a': 2, 'b': 5}

Or using + :

from pprint import pprint
from collections import Counter

x={'a':1,'b':2}
y={'a':1,'b':3}

pprint(dict(Counter(x) + Counter(y)))

Answer 2

collections.Counter is the natural method, but you can also use a dictionary comprehension after calculating the union of your dictionary keys:

x = {'a':1, 'b':2}
y = {'a':1, 'b':3}

dict_tup = (x, y)

keys = set().union(*dict_tup)
z = {k: sum(i.get(k, 0) for i in dict_tup) for k in keys}

print(z)

{'a': 2, 'b': 5}

Answer 3

Code:

from collections import Counter

x = {"a":1, "b":2}
y = {"a":1, "b":3}

c = Counter(x)
c += Counter(y)
z = dict(c)
print(z)

Output:

{'a': 2, 'b': 5}