python getting json values from list-CodePudding

I have some json data similar to this...

    {
        "people": [
            {
                "name": "billy",
                "age": "12"
                 ...
                 ...
            },
            {
                "name": "karl",
                "age": "31"
                 ...
                 ...
            },
            ...
            ...
        ]
    }

At the moment I can do this to get a entry from the people list...

wantedPerson = "karl"

for person in people:
    if person['name'] == wantedPerson:
        * I have the persons entry *
        break

Is there a better way of doing this? Something similar to how we can .get('key') ? Thanks, Chris

CodePudding user response：

Assuming you load that json data using the standard library for it, you're fairly close to optimal, perhaps you were looking for something like this:

from json import loads

text = '{"people": [{"name": "billy", "age": "12"}, {"name": "karl", "age": "31"}]}'

data = loads(text)

people = [p for p in data['people'] if p['name'] == 'karl']

If you frequently need to access this data, you might just do something like this:

all_people = {p['name']: p for p in data['people']}

print(all_people['karl'])

That is, all_people becomes a dictionary that uses the name as a key, so you can access any person in it quickly by accessing them by name. This assumes however that there are no duplicate names in your data.

CodePudding user response：

First, there's no problem with your current 'naive' approach - it's clear and efficient since you can't find the value you're looking for without scanning the list.

It seems that you refer to better as shorter, so if you want a one-liner solution, consider the following:

next((person for person in people if person.name == wantedPerson), None)

It gets the first person in the list that has the required name or None if no such person was found.

CodePudding user response：

similarly

ps =  {
        "people": [
            {
                "name": "billy",
                "age": "12"
    
            },
            {
                "name": "karl",
                "age": "31"
            },
        ]
    }

print([x for x in ps['people'] if 'karl' in x.values()])

For possible alternatives or details see e.g. # Get key by value in dictionary