how to merge similar observations by key attributes in json python

Im working with JSON in python, It new to me, and im trying to merge similar observations by key attributes. The JSON looks like this:

tempads=[
['doron-2020-026', ['19.0.1']],
['doron-2020-026', ['18.0.6']],
['doron-2020-023', ['19.0.0']],
['doron-2020-023', ['18.0.5']],
['doron-2020-023', ['17.0.7']]
]

I tried to create a list with unique observations using this:

    for tempad in tempads:
    ads.append(tempad[0])
ads = list(dict.fromkeys(ads))

the output is:

['doron-2020-026', 'doron-2020-023']

then I tried to look for that list values and to add to them the observations but for some reason, it’s only giving me back the latest one:

for ad in ads:
    for i in range(0,len(tempads)-1):
        if ad==tempads[i][0]:
            ad=[ad,tempads[i][1]]
            newads.append(ad)
print(newads)

[
['doron-2020-026', ['19.0.1']],
['doron-2020-023', ['19.0.0']]
]

Answer

Looks like you need a groupby.

Using itertools.groupby. Note this works only if the list is ordered.

Ex:

from itertools import groupby

tempads=[
    ['doron-2020-026', ['19.0.1']],
    ['doron-2020-026', ['18.0.6']],
    ['doron-2020-023', ['19.0.0']],
    ['doron-2020-023', ['18.0.5']],
    ['doron-2020-023', ['17.0.7']]
    ]

result = [[k, [n for _, i in v for n in i]] for k, v in groupby(tempads, lambda x: x[0])]
print(result)

Output:

[['doron-2020-026', ['19.0.1', '18.0.6']],
 ['doron-2020-023', ['19.0.0', '18.0.5', '17.0.7']]]

---

If the list is unordered use a simple dict

Ex:

result = {}
for k, v in tempads:
    result.setdefault(k, []).extend(v)

Output:

{'doron-2020-023': ['19.0.0', '18.0.5', '17.0.7'],
 'doron-2020-026': ['19.0.1', '18.0.6']}