Finding duplicates from array using Python

Question

I'm quite new to Python and was wondering if there was a good way to create a new list of unduplicated users.

My problem is that I have something like this

[
{
    "userId": "987654321",
    "method": "CARD",
    "lastDigits": "1234",
    "type": "mc",
    "first_name": "Leroy",
    "last_name": "Jenkins",
    "exp": "01/23"
  },
  {
    "userId": "987654321",
    "method": "PAYPAL",
    "first_name": "Leroy",
    "last_name": "Jenkins"
  },
  {
    "userId": "123456789",
    "method": "CARD",
    "lastDigits": "4567",
    "type": "visa",
    "first_name": "Joe",
    "last_name": "Bloggs",
    "exp": "01/25"
  },
  {
    "userId": "46513498000",
    "method": "PAYPAL",
    "first_name": "Betty",
    "last_name": "White"
  }
]

Basically I need to match when the userId has matched and keep the object when "method": "CARD" instead of PAYPAL then reconstruct essentially the same list again but minus the duplicate userId's when the user has both CARD and PAYPAL

::EDIT:: User can just have PAYPAL. and if it does just have PAYPAL, just return that

example output needed

[
{
    "userId": "987654321",
    "method": "CARD",
    "lastDigits": "1234",
    "type": "mc",
    "first_name": "Leroy",
    "last_name": "Jenkins",
    "exp": "01/23"
  },
  {
    "userId": "123456789",
    "method": "CARD",
    "lastDigits": "4567",
    "type": "visa",
    "first_name": "Joe",
    "last_name": "Bloggs",
    "exp": "01/25"
  },
  {
    "userId": "46513498000",
    "method": "PAYPAL",
    "first_name": "Betty",
    "last_name": "White"
  }
]

Answer 1

If I don't misunderstood your question then simple filtering will do the trick for you,

user_ids = []
final_users = []
for user in users:
    user_ids.append(int(user['userId']))
    if user['userId'] not in user_ids and user['method'] == 'CARD':
        final_users.append(user)
print(final_users)

Working Code: https://rextester.com/COBGVU63922

Answer 2

users = {}

for d in user_list:
    uid = d["userId"]
    # If user id not in users, we add it
    if uid not in users:
        users[uid] = d

    # Otherwise we check if the already recorded method was "PAYPAL", 
    # if so we overwrite it.
    elif users[uid]["method"] == "PAYPAL":
       users[uid] = d

# To convert dict we just created back to list:
user_list = list(users.values())
    

Answer 3

Use defaultdict :

from collections import defaultdict

newdata = defaultdict(dict)

for item in data:
    userid = newdata[item['userId']]
    if userid == {} and item['method'] == 'CARD':
        userid.update(item)

Output:

# newdata = list(newdata.values())
>>> newdata
[{'userId': '987654321',
  'method': 'CARD',
  'lastDigits': '1234',
  'type': 'mc',
  'first_name': 'Leroy',
  'last_name': 'Jenkins',
  'exp': '01/23'},
 {'userId': '123456789',
  'method': 'CARD',
  'lastDigits': '4567',
  'type': 'visa',
  'first_name': 'Joe',
  'last_name': 'Bloggs',
  'exp': '01/25'}]

Answer 4

This will perfectly work for your. Try and check it

mylist=[
{
    "userId": "987654321",
    "method": "CARD",
    "lastDigits": "1234",
    "type": "mc",
    "first_name": "Leroy",
    "last_name": "Jenkins",
    "exp": "01/23"
  },
  {
    "userId": "987654321",
    "method": "PAYPAL",
    "first_name": "Leroy",
    "last_name": "Jenkins"
  },
  {
    "userId": "123456789",
    "method": "CARD",
    "lastDigits": "4567",
    "type": "visa",
    "first_name": "Joe",
    "last_name": "Bloggs",
    "exp": "01/25"
  },
  {
    "userId": "46513498000",
    "method": "PAYPAL",
    "first_name": "Betty",
    "last_name": "White"
  }
]
temp_list=[]
temp_id=[]
for x in mylist:
    if int(x['userId']) not in temp_id:
        temp_list.append(x)
        temp_id.append(int(x["userId"]))

print(temp_list)