Python词典列表：如何判断值是否不存在

Question

I have a JSON query that returns a list of dictionaries that I want to modify. Here is the part that interests me in the response:

{
    #...
    "publisher_bid_modifier": {
        "values": [{
                "target": "msn-can",
                "cpc_modification": 1.5
            },
            {
                "target": "msn-can-home",
                "cpc_modification": 1.5
            }
        ]
    }
}

The print(temp) in the code below will return:

[{"target": "msn-can-home","cpc_modification": 0.5}, {"target": "msn-can","cpc_modification": 0.5}]

After that, I extract the data I want to modify from the db and match it with the data extracted from the JSON response.

I can easily modify "cpc_modification" if the value of "target" exists in the db. My problem is to be able to do something else when the "target" value doesn't exist in the response.

Here is what I've done so far:

print(temp)

for dt in temp:
    theCursor.execute('SELECT ADJUST, SITE FROM SandboxPubTB WHERE CAMPAIGNNAME =?', (campaignName,) ) 
    campaignRows = theCursor.fetchall()
    for t in campaignRows:

        if t[1] == dt['target'] :
            dt['cpc_modification'] = "{:.2f}".format((int(t[0]) / 100) + 1)
            print("exists")
        #if dt['target'] not in t[1] :
        else:
            temp.append({'target': '"' + t[1] + "'", 'cpc_modification': "'" + str(t[0]) + "'"})
            print("Doesn't exists") 

print(temp) 

In the else I'm trying to append a new list entry with the new "target" and "cpc_modification" but the output is an infinite loop of the the print("Doesn't exists").

The closest I came to the solution is this:

elif dt['target'] not in temp:

But this will iterate as many time as the number of entries in the temp list.

To give an example with input and output:

Input:

[{
    'target': 'msn-can',
    'cpc_modification': 1.5
}, {
    'target': 'msn-can-home',
    'cpc_modification': 1.5
}, {
    'target': 'foxnews-foxnews',
    'cpc_modification': 1.5
}, {
    'target': 'beachraider',
    'cpc_modification': 0.69
}, {
    'target': 'crowdyfan',
    'cpc_modification': 0.7
}, {
    'target': 'novelodge',
    'cpc_modification': 0.75
}, {
    'target': 'foxnews-androidapp',
    'cpc_modification': 0.5
}, {
    'target': 'foxnews-foxbusiness',
    'cpc_modification': 1.12
}, {
    'target': 'foxnews-iosapp',
    'cpc_modification': 0.86
}, {
    'target': 'thehindu-hindunews',
    'cpc_modification': 0.7
}, {
    'target': 'vitaminnews',
    'cpc_modification': 1.46
}]

Database:

Output:

[{
    'target': 'msn-can',
    'cpc_modification': 0.5 <----
}, {
    'target': 'msn-can-home',
    'cpc_modification': 0.5 <----
}, {
    'target': 'foxnews-foxnews',
    'cpc_modification': 1.5
}, {
    'target': 'beachraider',
    'cpc_modification': 0.69
}, {
    'target': 'crowdyfan',
    'cpc_modification': 0.7
}, {
    'target': 'novelodge',
    'cpc_modification': 0.75
}, {
    'target': 'foxnews-androidapp',
    'cpc_modification': 0.5
}, {
    'target': 'foxnews-foxbusiness',
    'cpc_modification': 1.12
}, {
    'target': 'foxnews-iosapp',
    'cpc_modification': 0.86
}, {
    'target': 'thehindu-hindunews',
    'cpc_modification': 0.7
}, {
    'target': 'vitaminnews',
    'cpc_modification': 1.46
}], {
    'target': 'msn-outlookcom-canada', <----
    'cpc_modification': 0.5 <----
}]

Your help will be much appreciated. Thank you!

EDIT

The code above addresses only one campaign *campaignName variable", but the whole code should be able to treat more than one campaign. So here is an other example:

input

Campaign 1:

[{
    'target': 'msn-can',
    'cpc_modification': 0.5
}, {
    'target': 'msn-can-home',
    'cpc_modification': 0.5
}]

Campaign 2:

[{
    'target': 'fox-news',
    'cpc_modification': 0.9
}, {
    'target': 'fox-news-home',
    'cpc_modification': 0.6
}]

data in db

Campaign 1:

target: msn-can, cpc_modification: 7
target: msn-can-home, cpc_modification: 10

Campaign 2:

target: fox-news, cpc_modification: 20
target: fox-news-home, cpc_modification: 30
target: msn-us, cpc_modification: 10

Output

Campaign 1:

[{
    'target': 'msn-can',
    'cpc_modification': 1.07
}, {
    'target': 'msn-can-home',
    'cpc_modification': 1.1
}]

Campaign 2:

[{
    'target': 'fox-news',
    'cpc_modification': 1.2
}, {
    'target': 'fox-news-home',
    'cpc_modification': 1.3
}], {
    'target': 'msn-us',
    'cpc_modification': 1.1
}]

Answer 1

re-group your data so that you have a dictionary keyed by the target.

rekey = {t['target']: t for t in temp}

then you can just look for your data naturally

theCursor.execute('SELECT ADJUST, SITE FROM SandboxPubTB WHERE CAMPAIGNNAME =?', (campaignName,) ) 
campaignRows = theCursor.fetchall()
for t in campaignRows:
    fmt_value = "{:.2f}".format((int(t[0]) / 100) + 1)
    try:
        print(f"updating {t[1]}")
        rekey[t[1]]['cpc_modification'] = fmt_value
    except KeyError:
        print(f"Adding new key {t[1]}")
        rekey[t[1]] = {'target': t[1], 'cpc_modification': fmt_value}

from pprint import pprint
pprint(rekey.values())