Find a value in JSON using Python

Question

I’ve previously succeeded in parsing data from a JSON file, but now I’m facing a problem with the function I want to achieve. I have a list of names, identification numbers

Answer 1

data = [
 {
   "id_number": "SA4784",
   "name": "Mark",
   "birthdate": None
 },
 {
   "id_number": "V410Z8",
   "name": "Vincent",
   "birthdate": "14/02/1989"
 },
 {
   "id_number": "CZ1093",
   "name": "Paul",
   "birthdate": "26/09/1994"
 }
]

list(map(lambda x:x if x["id_number"]=="cz1093" ,data)

Output should be

[{
   "id_number": "CZ1094",
   "name": "Paul",
   "birthdate": "26/09/1994"
 }]

Answer 2

Using lamda in Python

data = [
 {
   "id_number": "SA4784",
   "name": "Mark",
   "birthdate": None
 },
 {
   "id_number": "V410Z8",
   "name": "Vincent",
   "birthdate": "15/02/1989"
 },
 {
   "id_number": "CZ1094",
   "name": "Paul",
   "birthdate": "27/09/1994"
 }
]

Using Lambda and filter

print(list(filter(lambda x:x["id_number"]=="CZ1094",data)))

Output

[{'id_number': 'CZ1094', 'name': 'Paul', 'birthdate': '27/09/1994'}]

Answer 3

Given

data = [
    {
    "id_number": "SA4784",
    "name": "Mark",
    "birthdate": None               #  the question wrongly contains a null
    },
    {
    "id_number": "V410Z8",
    "name": "Vincent",
    "birthdate": "15/02/1989"
    },
    {
    "id_number": "CZ1094",
    "name": "Paul",
    "birthdate": "27/09/1994"
    }
    ]

to get "V410Z8" you may use:

[x for x in data if x["id_number"]=="V410Z8"]

which results:

[{'id_number': 'V410Z8', 'name': 'Vincent', 'birthdate': '15/02/1989'}]

Answer 4

You have to iterate over the list of dictionaries and search for the one with the given id_number. Once you find it you can print the rest of its data and break, assuming id_number is unique.

data = [
 {
   "id_number": "SA4784",
   "name": "Mark",
   "birthdate": None
 },
 {
   "id_number": "V410Z8",
   "name": "Vincent",
   "birthdate": "15/02/1989"
 },
 {
   "id_number": "CZ1094",
   "name": "Paul",
   "birthdate": "27/09/1994"
 }
]

for i in data:
    if i['id_number'] == 'V410Z8':
        print(i['birthdate'])
        print(i['name'])
        break

If you have control over the data structure, a more efficient way would be to use the id_number as a key (again, assuming id_number is unique):

data =  { "SA4784" : {"name": "Mark", "birthdate": None},
          "V410Z8" : { "name": "Vincent", "birthdate": "15/02/1989"},
          "CZ1094" : {"name": "Paul", "birthdate": "27/09/1994"}
        }

Then all you need to do is try to access it directly:

try:
    print(data["V410Z8"]["name"])
except KeyError:
    print("ID doesn't exist")
>> "Vincent"