DeleteMissing

DeleteMissing[list] drops elements with head Missing from a list.

DeleteMissing[assoc] drops elements whose values have head Missing from an association.

DeleteMissing[expr, n] applies DeleteMissing to lists or associations within the first n levels of expr.

Examples

Remove missing values:

DeleteMissing[{1, Missing[], 2, Missing["NotFound"], 3}]
(* {1, 2, 3} *)

From an association:

DeleteMissing[<|"a" -> 1, "b" -> Missing[], "c" -> 3|>]
(* <|"a" -> 1, "c" -> 3|> *)

Please visit the official Wolfram Language Reference for more details.