如何将新密钥添加到与现有密钥对应的字典中

Question

我正在根据 SQLite 查询构建一个字典，该字典根据其前面的键对某个值求和。我想要做的是将 SQLite 查询之外的键值插入从所述查询创建的字典中。

EX：

query_3 = cur.execute('''SELECT upc AS upc,
                               description AS desc,
                               department AS dept_no,
                               substr((datetime),1,4) AS year,
                               substr((datetime),6,2) AS month,
                               sum(total) AS spend,
                               count(distinct(substr((datetime),12,2) || register_no ||
                                       emp_no || trans_no)) as Transactions,
                               sum(CASE WHEN (trans_status = 'V' or trans_status = 'R') THEN -1 ELSE 1 END) as Items
                               FROM transactions
                               WHERE department != 0 and
                                    department != 15 and
                                    trans_status != 'M' and
                                    trans_status != 'C' and
                                    trans_status != 'J' and
                                   (trans_status = '' or 
                                    trans_status = ' ' or 
                                    trans_status = 'V' or 
                                    trans_status = 'R')
                      GROUP BY desc, year, month''')

d3 = defaultdict(lambda: defaultdict(lambda: defaultdict(lambda: defaultdict(lambda: defaultdict(lambda: defaultdict(lambda: defaultdict(lambda: defaultdict(int))))))))

for row in cur.fetchall() :
    upc, desc, dept_no, year, month, spend, transactions, items = row

d3[upc][desc][dept_no][year][month]['spend'] += spend
d3[upc][desc][dept_no][year][month]['trans'] += transactions
d3[upc][desc][dept_no][year][month]['items'] += items

我想要做的是在dict [dept_name]中的[dept_no]键后添加d3键。我用相应的dept_no / dept_names创建了一个单独的字典，我只是不知道如何将它们合并到我的字典d3中。

Answer 1

如果我理解正确，这样就可以了。

d3[upc][desc][dept_no]['dept_name'] = "Something"

您只需为其指定一个值，即可在现有字典中创建一个键。

示例：

mydict = {'something': 1,'something2': 2}
print(mydict)
>>> {'something': 1, 'something2': 2} # print shows 2 values

mydict['something3'] = 3 # add a new key
print(mydict)
>>> {'something': 1, 'something3': 3, 'something2': 2} # now print shows 3 values, which confirms that we added a new key and value to the dict.