Lambda >>> add_one = lambda x: x + 1 >>> add_one(2) 3 Map >>> str_nums = ["4", "8", "6", "5", "3", "2", "8", "9", "2", "5"] >>> int_nums = map(int, str_nums) >>> int_nums <map object at 0x7fb2c7e34c70> >>> list(int_nums) [4, 8, 6, 5, 3, 2, 8, 9, 2, 5] >>> str_nums ["4", "8", "6", "5", "3", "2", "8", "9", "2", "5"] >>> numbers = [1, 2, 3, 4, 5] >>> squared = map(lambda num: num ** 2, numbers) >>> list(squared) [1, 4, 9, 16, 25] Filter >>> numbers = [-2, -1, 0, 1, 2] >>> # Using a lambda function >>> positive_numbers = filter(lambda n: n > 0, numbers) >>> positive_numbers <filter object at 0x7f3632683610> >>> list(positive_numbers) [1, 2] >>> # Using a user-defined function >>> def is_positive(n): ... return n > 0 ... >>> list(filter(is_positive, numbers)) [1, 2] Reduce >>> def my_add(a, b): ... result = a + b ... print(f"{a} + {b} = {result}") ... return result >>> my_add(5, 5) 5 + 5 = 10 10 >>> from functools import reduce >>> numbers = [0, 1, 2, 3, 4] >>> reduce(my_add, numbers) 0 + 1 = 1 1 + 2 = 3 3 + 3 = 6 6 + 4 = 10 10 >>> from functools import reduce >>> numbers = [0, 1, 2, 3, 4] >>> reduce(my_add, numbers, 100) 100 + 0 = 100 100 + 1 = 101 101 + 2 = 103 103 + 3 = 106 106 + 4 = 110 110 >>> from functools import reduce >>> numbers = [1, 2, 3, 4] >>> reduce(lambda a, b: a + b, numbers) 10