Product Catalog Data Analysis

Objective

How is list price distributed across categories, and how much of the catalog is actually purchasable right now?

A product export was parsed with Python's csv module and reduced with loops, dictionaries, and conditional logic — no dataframe library. Prices were cleaned and cast to numeric, records with missing or malformed prices were quarantined, and category-level averages were computed from the cleaned set.

1. Step 1

   Parse defensively

   csv.DictReader reads the export; each price is stripped of currency symbols and thousands separators before a float cast inside a try/except.

2. Step 2

   Quarantine bad rows

   Rows that fail the cast are collected into a rejects list rather than silently dropped, so the excluded count is reportable.

3. Step 3

   Aggregate with dictionaries

   A category-keyed dictionary accumulates a running sum and count, giving averages in a single pass over the file.

4. Step 4

   Profile availability

   Availability flags are normalized to lowercase and counted, then expressed as a share of the cleaned record set.

import csv
from collections import defaultdict

totals = defaultdict(lambda: {"sum": 0.0, "count": 0})
rejects = []
available = 0

with open("products.csv", newline="", encoding="utf-8") as fh:
    for row in csv.DictReader(fh):
        raw = (row.get("price") or "").replace("$", "").replace(",", "").strip()
        try:
            price = float(raw)
        except ValueError:
            rejects.append(row.get("product_id"))
            continue

        category = (row.get("category") or "uncategorized").strip().title()
        totals[category]["sum"] += price
        totals[category]["count"] += 1

        if (row.get("availability") or "").strip().lower() == "available":
            available += 1

averages = {
    cat: round(v["sum"] / v["count"], 2)
    for cat, v in totals.items()
    if v["count"]
}

for cat, avg in sorted(averages.items(), key=lambda kv: -kv[1]):
    print(f"{cat:<14} {avg:>8.2f}  (n={totals[cat]['count']})")

print(f"available: {available}  rejected rows: {len(rejects)}")

• 462 records carried a usable numeric price after cleaning; malformed rows were logged rather than dropped silently.
• 426 products (92.2%) are flagged available, so catalog breadth and purchasable breadth are close but not identical.
• Actuators show the highest average list price at approximately $100.28.
• Just over half the catalog sits between $25 and $75, which pulls the overall mean below the perceived positioning of the top categories.