合并列表，同时在python中显示零 [英] Merge lists while showing zeros in python

问题描述

我创建了一个Django QuerySet来对值进行计数，但是不幸的是它不显示0个值.因此，我想像SQL中的左联接那样合并我的两个列表.我显示我的输入和期望的输出.

I created a Django QuerySet which count values but unfortunately it do not show 0 values. Therefore I want to merge my two list like left join in SQL. I show my inputs and desired outputs .

输入1(Django查询1):

我这样打印出来:

for i in query_1:
     print (i['day'], i['count_1'])  

2018-01-17 00:00:00+01:00 49
2018-01-16 00:00:00+01:00 139
2018-01-15 00:00:00+01:00 144
2018-01-14 00:00:00+01:00 142
2018-01-13 00:00:00+01:00 141
2018-01-12 00:00:00+01:00 144
2018-01-11 00:00:00+01:00 145
2018-01-10 00:00:00+01:00 95

输入2(Django查询2):

我这样打印出来:

    for i in query_2:
         print (i['day'], i['count_2'])  

   2018-01-17 00:00:00+01:00 2
   2018-01-16 00:00:00+01:00 6
   2018-01-14 00:00:00+01:00 2
   2018-01-13 00:00:00+01:00 4

我想要的输出是:

2018-01-17 00:00:00+01:00 49  2
2018-01-16 00:00:00+01:00 139 6
2018-01-15 00:00:00+01:00 144 0
2018-01-14 00:00:00+01:00 142 2
2018-01-13 00:00:00+01:00 141 4
2018-01-12 00:00:00+01:00 144 0
2018-01-11 00:00:00+01:00 145 0
2018-01-10 00:00:00+01:00 95  0 

我尝试了这个，但是失败了:

I tried this but I failed:

for a, b in zip (query_1, query_2)
    if a['day'] == b['day']:
       print (a['count_2']) #It prints only the result of query_2 not both :(
    else:
       print ('0') 

推荐答案

new_data = [ i['day'] + ' ' + str(i['count_1']) for i in query_1]  
new_data.extend([ i['day'] + ' ' + str(i['count_1']) for i in query_2])
local_dict = {}
for values in new_data:
    date, time, val = values.split()
    if date in local_dict:
        new_value = local_dict[date]
        local_dict[date] = new_value.replace(new_value[-1],val)
    else:
        local_dict.setdefault(date,values+ (' %s' % '0'))
print(local_dict.values())
>>>
["2018-01-17 00:00:00+01:00 49  2",
"2018-01-16 00:00:00+01:00 139 6",
"2018-01-15 00:00:00+01:00 144 0",
"2018-01-14 00:00:00+01:00 142 2",
"2018-01-13 00:00:00+01:00 141 4",
"2018-01-12 00:00:00+01:00 144 0",
"2018-01-11 00:00:00+01:00 145 0",
"2018-01-10 00:00:00+01:00 95  0"]

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