As ZdaR's post illustrates, to create a json, you need to build the corresponding Python data structure (lists for json arrays, dictionaries for json objects) and serialize it at the end. So the question is almost the same as how to create a list in a loop, because after creating the list, what remains is serialization which is as simple as json.loads(data).

The task in the OP can be done in two loops:

data = [{'Title': line.getText(strip=True)} for line in games_html.findAll('a')]

for i, line in enumerate(games_html.findAll('div', class_="product_score")):
    data[i]['Score'] = line.getText(strip=True)

# serialize to json array
j = json.dumps(data)

# or write to a file
with open('data.json', 'w') as f:
    json.dump(data, f)

Your JSON file is incorrect. Normally you must have a structure as:

{
    "key1": [
        {
            "id": "blabla",
            "name": "Toto"
        },
        {
            "id": "blibli",
            "name": "Tata"
        }
    ],
    "key2": {
        "id": "value"
    },
    "key3": "value"
}

So I think you have to change your JSON array for example as following:

{
    [
        {
            "id": 0,
            "organizer": "Some Name",
            "eventStart": "09:30 AM",
            "eventEnd": "10:00 AM",
            "subject": "rental procedure",
            "attendees": "Some Name<br />Person 2<br />Person 3"
        },
        {
            "id": 1,
            "organizer": "Some Name",
            "eventStart": "09:30 AM",
            "eventEnd": "10:00 AM",
            "subject": "rental procedure",
            "attendees": "Some Name<br />Person 2<br />Person 3"
        },
        {
            "id": 2,
            "organizer": "Some Name",
            "eventStart": "09:30 AM",
            "eventEnd": "10:00 AM",
            "subject": "rental procedure",
            "attendees": "Some Name<br />Person 2<br />Person 3"
        }
    ]
}

You can decide also to have not a list of dictionary as I proposed above but to use the ID value as key for each dictionary; in that case you have:

{
    "id0":{       
            "organizer": "Some Name",
            "eventStart": "09:30 AM",
            "eventEnd": "10:00 AM",
            "subject": "rental procedure",
            "attendees": "Some Name<br />Person 2<br />Person 3"
    },
    "id1":{       
            "organizer": "Some Name",
            "eventStart": "09:30 AM",
            "eventEnd": "10:00 AM",
            "subject": "rental procedure",
            "attendees": "Some Name<br />Person 2<br />Person 3"
    },
    "id2":{       
            "organizer": "Some Name",
            "eventStart": "09:30 AM",
            "eventEnd": "10:00 AM",
            "subject": "rental procedure",
            "attendees": "Some Name<br />Person 2<br />Person 3"
    }
}

As explained by others (in answers) you should create a new dictionary for each item on the list elsewhere you reference always the same dictionary

import json
part_nums = ['ECA-1EHG102','CL05B103KB5NNNC','CC0402KRX5R8BB104']

def json_list(list):
    lst = []
    for pn in list:
        d = {}
        d['mpn']=pn
        lst.append(d)
    return json.dumps(lst)

print json_list(part_nums)

print

[{"mpn": "ECA-1EHG102"}, {"mpn": "CL05B103KB5NNNC"}, {"mpn": "CC0402KRX5R8BB104"}]

JSON doesn't allow extra commas at the end of an array or object. But your code adds such an extra comma. If you look at the official grammar here, you can only have a , before another value. And Python's json library conforms to that grammar, so:

>>> json.loads('[1, 2, 3, ]')
ValueError: Expecting value: line 1 column 8 (char 7)

To fix this, you could do something like this:

first = True
for task in l:
    if (task['Name'] == 'dinner'):  #criteria for desirable tasks
        if first:
            first = False
        else:
            a.write(',')
        j = json.dumps(task)
        a.write(str(j))   

On the other hand, if memory isn't an issue, it might be simpler—and certainly cleaner—to just add all of the objects to a list and then json.dumps that list:

output = []
for task in l:
    if (task['Name'] == 'dinner'):  #criteria for desirable tasks
        output.append(task)
a.write(json.dumps(output))

Or, more simply:

json.dump([task for task in l if task['Name'] == 'dinner'], a)

(In fact, even if memory is an issue, you can extend JSONEncoder, as shown in the docs, to handle iterators by converting them lazily into JSON arrays, but this is a bit tricky, so I won't show the details unless someone needs them.)

I think you need to make sure you're declaring pickup_records as a list, and then check the way you're calling json.dumps.

pickup_records = []
for tmpPickUp in pickup:
    pickup_date=tmpPickUp.pickup_date
    pickup_time=tmpPickUp.pickup_time
    pickup_id = tmpPickUp.id
    pickup_name=tmpPickUp.customer_name
    pickup_number=tmpPickUp.pieces
    print pickup_date,pickup_time,pickup_id,pickup_name,pickup_number
    record = {"name":pickup_name, "id":pickup_id,"time":pickup_date,"number":pickup_number,"status":"1"}
    pickup_records.append(record)
pickup_records = json.dumps({'pickups': pickup_records}, indent=4) 
pickup_response={"pickup":pickup_records}
return HttpResponse(pickup_response, content_type="application/json")

UPDATE

I've run the following in a console - (I think the error must be with your TmpPickUp items) -

>>> import json
>>> records = []
>>> for i in ["","",""]:
...     record = {"name":i, "id":i,"time":i,"number":i,"status":i}
...     records.append(record)
... 
>>> print json.dumps({'pickups': records}, indent=4)
{
    "pickups": [
        {
            "status": "", 
            "time": "", 
            "number": "", 
            "name": "", 
            "id": ""
        }, 
        {
            "status": "", 
            "time": "", 
            "number": "", 
            "name": "", 
            "id": ""
        }, 
        {
            "status": "", 
            "time": "", 
            "number": "", 
            "name": "", 
            "id": ""
        }
    ]
}

You can try like below to get the values from json response:

import json

content=[{
    "username": "admin",
    "first_name": "",
    "last_name": "",
    "roles": "system_admin system_user",
    "locale": "en",
    "delete_at": 0,
    "update_at": 1511335509393,
    "create_at": 1511335500662,
    "auth_service": "",
    "email": "[email protected]",
    "auth_data": "",
    "position": "",
    "nickname": "",
    "id": "pbjds5wmsp8cxr993nmc6ozodh"
}, {
    "username": "chatops",
    "first_name": "",
    "last_name": "",
    "roles": "system_user",
    "locale": "en",
    "delete_at": 0,
    "update_at": 1511335743479,
    "create_at": 1511335743393,
    "auth_service": "",
    "email": "[email protected]",
    "auth_data": "",
    "position": "",
    "nickname": "",
    "id": "akxdddp5p7fjirxq7whhntq1nr"
}]

for item in content:
    print("Name: {}\nEmail: {}\nID: {}\n".format(item['username'],item['email'],item['id']))

Output:

Name: admin
Email: [email protected]
ID: pbjds5wmsp8cxr993nmc6ozodh

Name: chatops
Email: [email protected]
ID: akxdddp5p7fjirxq7whhntq1nr

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