Question

我有一个字典“celldict”，其中包含以下元素：

{1224:{'A': 6, 'B': 4, 'C': 5}, 1225: {'A': 6, 'B': 6, 'C': 5}}

我想为每个键计算A + B，并得到如下结果：

{1224:{'A': 6, 'B': 4, 'C': 5,'AB' : 10}, 1225: {'A': 6, 'B': 6, 'C': 5, 'AB' :12 }}

所以我这样做了：

a = ["A","B"]

for num in celldict :
    found =0
    sum = 0

    for key in a :
        if key in celldict[num][key]:
            print "ignoring existing key"
        else : 
            print "continuing"
            continue
            sum += celldict[num][key]
            found = 1

    if found == 1 : 
        celldict[num]["AB"] = sum 

print   celldict

但它不起作用，发现总是返回0，我做错了也许当我试图检查我的词典中是否存在密钥时。任何帮助将不胜感激，谢谢。

Answer 1

使用快速生成器循环和sum()函数：

会更简单

sumkey = ''.join(a)
for num in celldict:
    num[sumkey] = sum(num.get(k, 0) for k in a)

此解决方案是通用的，您可以向a添加额外的密钥，它将继续有效。

Answer 2

continue语句将跳过循环中的其余代码并开始新的迭代。这里没有理由使用它 - 您应该将其删除，以便sum += celldict[num][key]行实际执行。

你也可以更简单地写下这整篇文章：

for d in celldict.values():
    d['AB'] = d.get('A',0) + d.get('B',0)

Answer 3

继续之后的任何内容都将在else块中运行

Answer 4

一个简短的解决方案是：

def sum_keys(d, keys=["A","B"]):
    #iterate over all the dictionaries in d
    for subdict in d.values():
        #check that all required keys are in the dict
        if not all(k in subdict for k in keys): continue
        #create the sum and assign it
        subdict[''.join(keys)] = sum(subdict[k] for k in keys)

Answer 5

In [29]: for item in celldict:
   ....:     if celldict[item].has_key('A') and celldict[item].has_key('B'):
   ....:         celldict[item]['AB'] = celldict[item]['A'] + celldict[item]['B']
   ....:

In [30]: celldict
Out[30]:
{1224: {'A': 6, 'AB': 10, 'B': 4, 'C': 5},
 1225: {'A': 6, 'AB': 12, 'B': 6, 'C': 5}}

Answer 6

celldict = {1224:{'A': 6, 'B': 4, 'C': 5}, 1225: {'A': 6, 'B': 4, 'C': 5}}
count_keys = ["A","B"]
counted_key = "AB"

for item in celldict.values():
    item[counted_key] = 0

    for key in count_keys:
        item[counted_key] += item[key]

print(celldict)

双级字典python中的sum值

6 个答案: