fn_registry/python/functions/datascience/aggregate_by_group.md

name, kind, lang, domain, version, purity, signature, description, tags, uses_functions, uses_types, returns, returns_optional, error_type, imports, tested, tests, test_file_path, file_path

name	kind	lang	domain	version	purity	signature	description	tags	uses_functions	uses_types	returns	returns_optional	error_type	imports	tested	tests	test_file_path	file_path
aggregate_by_group	function	py	datascience	1.0.0	pure	def aggregate_by_group(rows: list[dict], group_by: list[str], aggs: dict[str, str]) -> list[dict]	GROUP BY + agregaciones sobre datos tabulares. aggs es un dict de columna a funcion (sum, mean, count, min, max, first, last, collect). collect acumula valores en lista. None se ignora en agregaciones numericas.	datascience tabular groupby aggregate transform python				false		collections	true	Group by una columna con sum Group by multiples columnas Agregacion mean count min max collect acumula en lista Grupo con una sola fila Campo con None se ignora en agregaciones numericas	python/functions/datascience/aggregate_by_group_test.py	python/functions/datascience/aggregate_by_group.py

Ejemplo

rows = [
    {"dept": "eng", "salary": 100},
    {"dept": "eng", "salary": 120},
    {"dept": "sales", "salary": 80},
]
aggregate_by_group(rows, group_by=["dept"], aggs={"salary": "mean"})
# [{"dept": "eng", "salary": 110.0}, {"dept": "sales", "salary": 80.0}]

Notas

Funcion pura sin dependencias externas (solo collections.defaultdict de stdlib). Preserva el orden de primera aparicion de cada grupo. La funcion 'collect' no filtra None — acumula todos los valores incluyendo None.