Search by value of dict in array-CodePudding

I have a large list of dicts, each dict has a token.

large_list = [{"token": "4kj13", "value1": 10, "value2": 20},
              {"token": "hm9gm", "value1": 15, "value2": 30}]

I need to quickly find a dictionary by token, something like

print(large_list["4kj13"]["value1"])

Is there any elegant way to do it? I think I can create a dictionary token to index:

token2index = {"4kj13": 0, "hm9gm": 1}

But if there's a better solution, then I would be glad to know.
I can't change the input format (json), though I can create some intermediate data.

UPD: also the content of the dict is not simple, so the list can't be easily transformed to a table
UPD2: tokens are unique

CodePudding user response：

Convert list of dict to dict

d = {x["token"]: x for x in large_list}
d["4kj13"]["value1"]
# 10

CodePudding user response：

To get the index of a specific dict, you can use next with an enumerator:

def get_token(token):
    try:
        return next(i for i,di in enumerate(large_list) if di['token']==token)
    except StopIteration:
        raise ValueError

>>> large_list[get_token("4kj13")]
{'token': '4kj13', 'value1': 10, 'value2': 20}

>>> large_list[get_token("4kj13")]['value1']
10

If the specific token is not found, it raises a ValueError in the same manner as list.index:

>>> large_list[get_token("4kj1")]
Traceback (most recent call last):
  File "<stdin>", line 3, in get_token
StopIteration

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 5, in get_token
ValueError

Or you can use next with a default value if that is simpler:

>>> next((i for i,di in enumerate(large_list) if di['token']=="hm9gm"),-1)
1
>>> next((i for i,di in enumerate(large_list) if di['token']=="hm"),-1)
-1