Reference library

OOP & classes

Classes, instances, methods, dataclasses, and object-oriented design in Python.

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OOP & classes easy

How to Count Items in a Python Class

A beginner-friendly Inventory class that stores item quantities in a dictionary and provides add, remove, count, and summary methods.

oop classes inventory
Python 
class Inventory:
    def __init__(self):
        self.items = {}

    def add(self, item, quantity=1):
        self.items[item] = self.items.get(item, 0) + quantity

    def remove(self, item, quantity=1):
        if item not in self.items:
            raise ValueError(f"{item} not in inventory")
        self.items[it…
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