key_by()

Creates an object composed of keys generated from the results of running each element of the given collection through the given iteratee.

Implementation

Args: collection: The collection to process. Should be a list of dictionaries. iteratee: The function to run each element of the collection through. Can be a string (in which case the value of the given key is used) or a callable. Returns: An object with the results of running the iteratee on each element of the collection as keys, and the element of the collection as the values.

Example

key_by([{'a': 1, 'b': 2}, {'a': 3, 'b': 4}], 'a')

Expected output: {1: {'a': 1, 'b': 2}, 3: {'a': 3, 'b': 4}}

Source Code

                        def key_by(
    collection: List[Dict[Any, Any]], iteratee: Union[str, Callable]
) -> Dict[Any, Dict[Any, Any]]:
    if isinstance(iteratee, str):

        def fn(x):
            return x.get(iteratee)
    else:
        fn = iteratee
    out: Dict[Any, Any] = {}
    for x in collection:
        out[fn(x)] = x
    return out
                    