Question

dict1 = {a: 5, b: 7}
dict2 = {a: 3, c: 1}

result {a:8, b:7, c:1}

如何获得结果？

Answer 1

这是一个可以做到这一点的单线：

dict1 = {'a': 5, 'b': 7}
dict2 = {'a': 3, 'c': 1}

result = {key: dict1.get(key, 0) + dict2.get(key, 0)
          for key in set(dict1) | set(dict2)}
# {'c': 1, 'b': 7, 'a': 8}

请注意set(dict1) | set(dict2)是两个词典的键集。如果密钥存在，则dict1.get(key, 0)会返回dict1[key]，否则会返回0。

Answer 2

您可以使用collections.Counter以这种方式实现添加+：

>>> from collections import Counter
>>> dict1 = Counter({'a': 5, 'b': 7})
>>> dict2 = Counter({'a': 3, 'c': 1})
>>> dict1 + dict2
Counter({'a': 8, 'b': 7, 'c': 1})

如果你真的想把结果作为dict，你可以在之后把它丢回：

>>> dict(dict1 + dict2)
{'a': 8, 'b': 7, 'c': 1}

Answer 3

这是一个很好的功能：

def merge_dictionaries(dict1, dict2):
    merged_dictionary = {}

    for key in dict1:
        if key in dict2:
            new_value = dict1[key] + dict2[key]
        else:
            new_value = dict1[key]

        merged_dictionary[key] = new_value

    for key in dict2:
        if key not in merged_dictionary:
            merged_dictionary[key] = dict2[key]

    return merged_dictionary

写作：

dict1 = {'a': 5, 'b': 7}
dict2 = {'a': 3, 'c': 1}
result = merge_dictionaries(dict1, dict2)

结果将是：

{'a': 8, 'b': 7, 'c': 1}

Answer 4

一种快速的字典理解方法，适用于接受+运算符的任何类。性能可能不是最佳的。

{
    **dict1,
    **{ k:(dict1[k]+v if k in dict1 else v)
        for k,v in dict2.items() }
}

Answer 5

Here is another approach but it is quite lengthy!

d1 = {'a': 5, 'b': 7}
d2 = {'a': 3, 'c': 1}

d={}
for i,j in d1.items():
    for k,l in d2.items():
        if i==k:
            c={i:j+l}
            d.update(c)
for i,j in d1.items():
    if i not in d:
        d.update({i:j})
for m,n in d2.items():
    if m not in d:
        d.update({m:n})

Answer 6

def merge_dicts(*dict_args):
    """
    Given any number of dictionaries, shallow copy and merge into a new dict, precedence goes to key-value pairs in latter dictionaries.
    """
    result = {}
    for dictionary in dict_args:
        result.update(dictionary)
    return result
   
x = {'a':1, 'b': 2}
y = {'b':10, 'c': 11}
z = merge_dicts(x, y)

print(z)

{'a': 1, 'b': 10, 'c': 11}

[Program finished]

添加两个词典中的值

6 个答案: