I want to create a list per user so i got this jsonfile:

 data =  [
    {
      "id": "1",  
      "price": 1,   
    }, 
    {  
      "id": "1", 
      "price": 10,  
    }, 
    {
      "id": "2", 
      "price": 3, 
    }, 
    {   
      "id": "1", 
      "price": 10, 
    }, 
    {  
      "id": "2",   
      "price":8,  
    }, 
  ]

I'm on python and I want to have a result like for the user with 'id':1 [1,10,10]

and for the user with "id": "2": [3,8]

so two lists corresponding to the prices according to the ids is it possible to do that in python ?

note, in fact user id are UUID type and randomly generated.

edit: quantity was a mistake all data are price and id, sorry

CodePudding user response：

collections.defaultdict to the rescue.

Assuming you really do have mixed quantitys and prices and you don't care about mixing them into the same list,

from collections import defaultdict

data = [
    {
        "id": "1",
        "price": 1,
    },
    {
        "id": "1",
        "price": 10,
    },
    {
        "id": "2",
        "quantity": 3,
    },
    {
        "id": "1",
        "price": 10,
    },
    {
        "id": "2",
        "price": 8,
    },
]

by_id = defaultdict(list)
for item in data:
    item = item.copy()  # we need to mutate the item
    id = item.pop("id")
    # whatever is the other value in the dict, grab that:
    other_value = item.popitem()[1]
    by_id[id].append(other_value)

print(dict(by_id))

The output is

{'1': [1, 10, 10], '2': [3, 8]}

If you actually only do have prices, the loop is simpler:

by_id = defaultdict(list)
for item in data:
    by_id[item["id"]].append(item.get("price"))

or

by_id = defaultdict(list)
for item in data:
    by_id[item["id"]].append(item["price"])

to fail fast when the price is missing.

CodePudding user response：

first : you structur data : {[]}, is not supported in python. assume your data is :

my_json = [
    {
      "id": "1",  
      "price": 1,   
    }, 
    {  
      "id": "1", 
      "price": 10,  
    }, 
    {
      "id": "2", 
      "quantity": 3, 
    }, 
    {   
      "id": "1", 
      "price": 10, 
    }, 
    {  
      "id": "2",   
      "price":8,  
    }, 
  ]

then you can achive with this:

results = {}
for data in my_json:
    if data.get('id') not in results:
        results[data.get('id')] = [data.get('price') or data.get('quantity')]
    else:
        results[data.get('id')].append(data.get('price') or data.get('quantity')) 
print(results)

output:

{'1': [1, 10, 10], '2': [3, 8]}

CodePudding user response：

Maybe like this:

data = [
    {
        "id": "1",
        "price": 1,
    },
    {
        "id": "1",
        "price": 10,
    },
    {
        "id": "2",
        "quantity": 3,
    },
    {
        "id": "1",
        "price": 10,
    },
    {
        "id": "2",
        "price": 8,
    }
]

result = {}
for item in data:

    try:
        result[item['id']].append(item.get('price'))
    except KeyError:
        result[item['id']] = [item.get('price')]

print(result)

Where None is put in place of the missing price for that entry, quantity key ignored.

Result:

{'1': [1, 10, 10], '2': [None, 8]}

CodePudding user response：

A simple loop that enumerates your list (it's not JSON) in conjunction with setdefault() is all you need:

data = [
    {
        "id": "1",
        "price": 1,
    },
    {
        "id": "1",
        "price": 10,
    },
    {
        "id": "2",
        "price": 3,
    },
    {
        "id": "1",
        "price": 10,
    },
    {
        "id": "2",
        "price": 8,
    }
]

dict_ = {}

for d in data:
    dict_.setdefault(d['id'], []).append(d['price'])

print(dict_)

Output:

{'1': [1, 10, 10], '2': [3, 8]}

Note:

This will fail (KeyError) if either 'id' or 'price' is missing from the dictionaries in the list