Python Higher order function map (), filter (), reduce ()

The map () function, which receives two parameters, one is a function, the other is a sequence, and map () acts on each element of the sequence in turn, and returns the result as a new sequence;

AA = [1, 2, 3, 4, 5]print ("", List (map (Lambda a:a * A, aa)))#Map-result = [1, 4, 9, 16, 2 5]       

The filter () function, which receives two parameters, one is a function, the other is a sequence, and filter () applies the passed function to each element sequentially, depending on whether the return value is true or false, whether the element is persisted or discarded, and the resulting sequence is a subset of all return values true;

AA = [1, 2, 3, 4, 5]print ("", List (filter (lambda a:a >=3, aa))#Filter-result = [3, 4, 5]       

The reduce () function, which acts on a sequence, must receive two parameters, where the reduce () function accumulates the result and the next element of the sequence, and the reduce () function returns only the result of the value, not the sequence. In Python3, the reduce () function is moved to the Functools package.

Import reduceaa= [1,2,3,4,5]print ("", Reduce (lambda A, B: (A * b), aa))#  Reduce-result =        

Python Higher order function map (), filter (), reduce ()