dictutils.ops.sum_by

dictutils.ops.sum_by(items, key, map)

Sum mapped values by key function or path.

Parameters:

• items (Iterable[Any]) – Collection to process

• key (Union[str, Callable[[Any], Any]]) – Path string or function to extract grouping key

• map (Callable[[Any], Any]) – Function to extract value to sum

Return type:

dict[Any, Any]

Returns:

Dictionary mapping keys to summed values

Example

>>> import json
>>> sales = [
...     {"region": "North", "amount": 100},
...     {"region": "South", "amount": 200},
...     {"region": "North", "amount": 150}
... ]
>>> result = sum_by(sales, "region", lambda x: x["amount"])
>>> print(json.dumps(result, indent=4))
{
    "North": 250,
    "South": 200
}