AS
Size: a a a
AS
PU
features <- my_dt[account_number %in% san]отдаст тебе таблицу из 2000 san и их строк, по всем колонкам
AS
PU
features[, .SD[1], by = account_number]
), и получишь нужный тебе результатPU
PU
AS
AS
PU
AS
PU
AS
PU
ЕТ
AS
ЕТ
AS
PU
ЕТ
ЕТ