README.md

In this exercise you will read in a delimited data file as a list of records. Each record will be an instance of InventoryItem. The format of the delimited file is unusual, but can be handled by the Python csv module with appropriate configuration.

For example, the first few lines of data/Inventory.txt contain:

Name|Price|Quantity
/Wankle rotary engine/|555.55|527
/Sousaphone w%/ stand/|333.33|123

Feather Duster|22.22|900

/Area 51 metal fragment/|9999.99|

Notice the delimiter used and the manner of escaping a delimiter within a field. Blank lines should be ignored. Your result should match the datatypes annotated in the Data Class.

files.json

{
  "Inventory.txt": "https://raw.githubusercontent.com/ine-rmotr-curriculum/data-serialization-with-python/master/serialization/data/Inventory.txt"
}

main.py

import csv
from dataclasses import dataclass

@dataclass
class InventoryItem:
    '''Class for keeping track of an item in inventory.'''
    name: str
    unit_price: float
    quantity_on_hand: int = 0

    def total_cost(self) -> float:
        return self.unit_price * self.quantity_on_hand
    
items = []  # List of dataclass objects in this variable

solutions.py

def solution_1():
    with open('data/Inventory.txt') as fh:
        inventory = csv.reader(fh, delimiter="|", 
                                   quotechar="/",
                                   escapechar="%")
        skip_header = next(inventory)
        for record in inventory:
            if not record:
                continue
            name = record[0]
            price = float(record[1])
            quantity = int(record[2].replace(',','')) if record[2] else 0
            record = InventoryItem(name, price, quantity)
            items.append(record)

tests.py

def test_structure():
    import pickle
    correct = pickle.load(open('data/Inventory.pkl', 'rb'))
    assert len(correct) == len(items), "Wrong number of records constructed"
    assert correct == items, "Error in one or more records"