''' two different classes are realated, but there is no inheritance going

on. this is called composition where one class makes use of code contained

in another class'''

class Clothing:

stock = {'name': [], 'material': [], 'amount': []}

def __init__(self, name):

material = ""

self.name = name

def add_item(self, name, material, amount):

Clothing.stock['name'].append(self.name)

Clothing.stock['material'].append(self.material)

Clothing.stock['amount'].append(amount)

def Stock_by_Material(self, material):

count = 0

n = 0

for item in Clothing.stock['material']:

if item == material:

count += Clothing.stock['amount'][n]

n += 1

return count

class shirt(Clothing):

material = "Cotton"

class pants(Clothing):

material = "Cotton"

polo = shirt("Polo")

sweatpants = pants("Sweatpants")

polo.add_item(polo.name, polo.material, 4)

sweatpants.add_item(sweatpants.name, sweatpants.material, 6)

current_stock = polo.Stock_by_Material("Cotton")

print(current_stock)