You can simply create a dictionary containing the values you are after and then convert it to json using json.dumps

import json
data = {}
data['a'] = ["12","34","23"]
data['b'] = ["13","14","45"]
json_data = json.dumps(data)
print json_data

Try:

data = json.load(open("data.txt", 'r'))

json.loads interprets a string as JSON data, while json.load takes a file object and reads it, then interprets it as JSON.

Usually the json will be a string and you will try and deserialise it into a object graph (which in python are typically are made up of maps and arrays).

so assuming your response is actually a string (eg that was retrieved from a HTTP request/endpoint) then you deserialise it with json.loads (the function is basically load from string), then you've got a map with a 'password' key, that is an array, so grab the first element from it.

import json

resp = '{ "password": [ "Ensure that this field has atleast 5 and atmost 50 characters" ] }'
print json.loads(resp)['password'][0]

If you arrived at this question simply looking for a way to read a json file into memory, then use the built-in json module.

with open(file_path, 'r') as f:
    data = json.load(f)

If you have a json string in memory that needs to be parsed, use json.loads() instead:

data = json.loads(my_json_string)

Either way, now data is converted into a Python data structure (list/dictionary) that may be (deeply) nested and you'll need Python methods to manipulate it.

If you arrived here looking for ways to get values under several keys as in the OP, then the question is about looping over a Python data structure. For a not-so-deeply-nested data structure, the most readable (and possibly the fastest) way is a list / dict comprehension. For example, for the requirement in the OP, a list comprehension does the job.

store_list = [{'name': item['name'], 'city': item['city']} for item in json_array]
# [{'name': 'Mall of America', 'city': 'Bloomington'}, {'name': 'Tempe Marketplace', 'city': 'Tempe'}]

Other types of common data manipulation:

1. For a nested list where each sub-list is a list of items in the json_array.

   store_list = [[item['name'], item['city']] for item in json_array]
   # [['Mall of America', 'Bloomington'], ['Tempe Marketplace', 'Tempe']]
   

2. For a dictionary of lists where each key-value pair is a category-values in the json_array.

   store_data = {'name': [], 'city': []}
   for item in json_array:
       store_data['name'].append(item['name'])
       store_data['city'].append(item['city'])
   # {'name': ['Mall of America', 'Tempe Marketplace'], 'city': ['Bloomington', 'Tempe']}
   

3. For a "transposed" nested list where each sub-list is a "category" in json_array.

   store_list = list(store_data.values())
   # [['Mall of America', 'Tempe Marketplace'], ['Bloomington', 'Tempe']]
   

Here is a copy of code which works fine for me,

import json

with open("test.json") as json_file:
    json_data = json.load(json_file)
    print(json_data)

with the data

{
    "a": [1,3,"asdf",true],
    "b": {
        "Hello": "world"
    }
}

You may want to wrap your json.load line with a try catch, because invalid JSON will cause a stacktrace error message.