First solution clear solution for Army Battles by CDG.Axel - python coding challenges

Enable Javascript in your browser and then refresh this page, for a much enhanced experience.

First solution solution in Clear category for Army Battles by CDG.Axel

class Warrior:
    pass


class Army:
    pass
    

class Warrior:
    health = 50
    attack = 5

    @property
    def is_alive(self):
        return self.health > 0

    def take_hit(self, unit: Warrior):
        self.health -= unit.attack
        return self.is_alive


class Knight(Warrior):
    attack = 7


def fight(unit_1, unit_2):
    while unit_1.is_alive and unit_2.is_alive:
        if unit_2.take_hit(unit_1):
            unit_1.take_hit(unit_2)
    return unit_1.is_alive


class Army:
    def __init__(self):
        self.units = []


    def add_units(self, unit: Warrior, count: int):
        self.units.extend([unit() for i in range(count)])

    @property
    def is_alive(self):
        return bool(self.units)

    @property
    def first_warrior(self) -> Warrior:
        return self.units[0]


class Battle:
    @staticmethod
    def fight(army1: Army, army2: Army):
        while army1.is_alive and army2.is_alive:
            if fight(army1.first_warrior, army2.first_warrior):
                army2.units.pop(0)
            else:
                army1.units.pop(0)
        return army1.is_alive

    

if __name__ == '__main__':
    #These "asserts" using only for self-checking and not necessary for auto-testing
    
    #fight tests
    chuck = Warrior()
    bruce = Warrior()
    carl = Knight()
    dave = Warrior()
    mark = Warrior()

    assert fight(chuck, bruce) == True
    assert fight(dave, carl) == False
    assert chuck.is_alive == True
    assert bruce.is_alive == False
    assert carl.is_alive == True
    assert dave.is_alive == False
    assert fight(carl, mark) == False
    assert carl.is_alive == False

    #battle tests
    my_army = Army()
    my_army.add_units(Knight, 3)
    
    enemy_army = Army()
    enemy_army.add_units(Warrior, 3)

    army_3 = Army()
    army_3.add_units(Warrior, 20)
    army_3.add_units(Knight, 5)
    
    army_4 = Army()
    army_4.add_units(Warrior, 30)

    battle = Battle()

    assert battle.fight(my_army, enemy_army) == True
    assert battle.fight(army_3, army_4) == False
    print("Coding complete? Let's try tests!")

Sept. 21, 2021

Comments:

entreoutros on Oct. 16, 2021, 8 p.m.
Hello! That's a nice solution! Can you say why health and attack can be defined without init but the army units list can't?

CDG.Axel on Oct. 16, 2021, 8:15 p.m.
Cause health and attack it's class property. It can be used without class instance creation. Instance creation doesn't create new list. But it can be done with assign. Look at this code for example (and try to run). <pre class='brush: python'>class ClassOne: elem = 100 lst = [1] print(ClassOne.elem, ClassOne.lst) a = ClassOne() a.elem = 30 a.lst.append(2) print(a.elem, ClassOne.elem) print(a.lst, ClassOne.lst) a.lst = [3] print(a.lst, ClassOne.lst) </pre>

entreoutros on Oct. 16, 2021, 8:30 p.m.
Thank you. I ran it here and saw that a.lst.append(2) appends to the list for the whole class, while a.lst = [3] changes the list only for the instance a. So if I had <pre class='brush: python'>class Army: units = [] def add_units(self, unit: Warrior, count: int): self.units.extend([unit() for i in range(count)]) </pre> then the function add_units would extend the units list for the whole Army class?

CDG.Axel on Oct. 16, 2021, 9:54 p.m.
you operate static class variable 'units' this way, own instance variable is absent and you can't do this: <pre class='brush: python'>def add_units(self, unit: Warrior, count: int): self.units = [unit() for i in range(count)] </pre> because it will erase previously added units. Btw you can inherit list class for Army - it has it's own constructor. I used it in my 59-lines Lancers solution: <a href="https://py.checkio.org/mission/the-lancers/publications/CDG.Axel/python-3/59-lines/">https://py.checkio.org/mission/the-lancers/publications/CDG.Axel/python-3/59-lines/</a>

entreoutros on Oct. 16, 2021, 9:57 p.m.
Thank you a lot!

CDG.Axel on Oct. 16, 2021, 8:26 p.m.
I meant static class property And try this too <pre class='brush: python'>class ClassOne: elem = 100 a = ClassOne() b = ClassOne() print(ClassOne.elem, a.elem, b.elem) a.elem = 20 print(ClassOne.elem, a.elem, b.elem) ClassOne.elem = 95 print(ClassOne.elem, a.elem, b.elem) b.elem = 30 print(ClassOne.elem, a.elem, b.elem) </pre>

Everything is Object

0 %

You ClassRoom Demo is Ready With the new tool CheckiO ClassRoom, you will be able to analyze your students' progress, have your own leaderboard, change missions order on the map, and so on.