Python Filter | Map | Reduce Quick Reminder

main.py

#!/usr/bin/python3
# -*- encoding: utf-8 -*-

import logging as log

from functools import reduce

log.basicConfig(level=log.INFO)


def main():
    """
        Simple filter + list comprehension
    """
    filtered_list = list(filter((lambda x: x % 2 == 0),
                         [x for x in range(0, 10001)]))

    log.info(f"There are {len(filtered_list)} even numbers from 0 to 10000")

    """
        Sample data 
    """
    pilots = [
        {
            "id": 10,
            "name": "Poe Dameron",
            "years": 14,
        },
        {
            "id": 2,
            "name": "Temmin 'Snap' Wexley",
            "years": 30,
        },
        {
            "id": 41,
            "name": "Tallissan Lintra",
            "years": 16,
        },
        {
            "id": 99,
            "name": "Ello Asty",
            "years": 22,
        }
    ]

    """
        Simple filter from data 
    """
    teen_pilots = list(filter((lambda pilot: pilot['years'] < 18), pilots))

    for pilot in teen_pilots:
        log.info(f"{pilot} is a teenager...")

    """
        Simple data transformation 
    """
    pilot_information = list(map(
        (lambda pilot: f"Pilot '{pilot['name']} is {pilot['years']} years old..."), pilots))

    for name in pilot_information:
        log.info(name)

    """
        Filter from transformed data 
    """
    not_teen_pilots_information = list(map((lambda pilot: f"{pilot['name']} is NOT a teenager"), filter(
        (lambda pilot: pilot['years'] >= 18), pilots)))

    for pilot_info in not_teen_pilots_information:
        log.info(f"{pilot_info}")

    """
        Reduce transformed data (not chained) 
    """
    pilot_ages = list(map((lambda pilot: pilot['years']), pilots))

    total_age = reduce((lambda p1, p2: p1 + p2), pilot_ages)

    log.info(f"The total age for those pilots is {total_age} years!")


if __name__ == "__main__":
    main()