---
files: [jar.py]
url: https://cdn.cs50.net/2022/fall/labs/6/jar/README.md
window: [terminal]
---

# Cookie Jar

<!-- https://giphy.com/gifs/sesame-street-cookie-Q73g0HDX6hW5G -->
![Cookie Monster](giphy1.gif){:.w-50}

{:.small}
Source: Sesame Street

Suppose that you'd like to implement a [cookie jar](https://en.wikipedia.org/wiki/Cookie_jar) in which to store cookies. In a file called `jar.py`, implement a `class` called `Jar` with these methods:

* `__init__` should initialize a cookie jar with the given `capacity`, which represents the maximum number of cookies that can fit in the cookie jar. If `capacity` is not a non-negative `int`, though, `__init__` should instead raise a `ValueError` (via `raise ValueError`).
* `__str__` should return a `str` with $$n$$ `🍪`, where $$n$$ is the number of cookies in the cookie jar. For instance, if there are 3 cookies in the cookie jar, then `str` should return `"🍪🍪🍪"`
* `deposit` should add `n` cookies to the cookie jar. If adding that many would exceed the cookie jar's capacity, though, `deposit` should instead raise a `ValueError`.
* `withdraw` should remove `n` cookies from the cookie jar. Nom nom nom. If there aren't that many cookies in the cookie jar, though, `withdraw` should instead raise a `ValueError`.
* `capacity` should return the cookie jar's capacity.
* `size` should return the number of cookies actually in the cookie jar.

Structure your `class` per the below. You may not alter these methods' parameters, but you may add your own methods.

```py
class Jar:
    def __init__(self, capacity=12):
        ...

    def __str__(self):
        ...

    def deposit(self, n):
        ...

    def withdraw(self, n):
        ...

    @property
    def capacity(self):
        ...

    @property
    def size(self):
        ...
```

## Demo

You're welcome, but not required, to implement a `main` function in which to test your class, so this is all we can demo!

![Cookie Monster](giphy2.gif){:.w-50}

{:.small}
Source: Sesame Street

## How to Test

Here's how to test your code manually:

* Define a `main` function in your `jar.py` file, wherein you create a new instance of `Jar` with `jar = Jar()`. Test this `jar` has the capacity it should by calling `print(str(jar.capacity))`. Be sure your program calls `main` at the bottom of the file, as via `main()`.
* Test that your `__str__` function works as intended by calling `print(str(jar))`.
* Try calling `jar.deposit(2)` to deposit two cookies. Calling `print(str(jar))` should now show you the same number of cookies you've deposited.
* Try calling `jar.withdraw(1)` to withdraw one cookie. Calling `print(str(jar))` should now show you one fewer cookie than you had before.
* Try experimenting with depositing and withdrawing various amounts of cookies. Are you unable to withdraw past the jar's size? Are you unable to deposit past the jar's capacity?

No `check50` for this one!

## How to Submit

No need to submit! This is a practice problem.