Python Represent a Person or Product as a Dictionary

A store stores a product name, price and stock amount.

What You Need to Understand

A dictionary represents one record as named fields. Compared with positional list indexes, key names make the meaning of each value explicit.

When to Use It

A store stores a product name, price and stock amount.

Step-by-Step Python Example

product = {"name": "Keyboard", "price": 49.9, "stock": 12}
print(product["name"])
product["stock"] -= 1
print(product)

How the Example Works

The dictionary uses keys for lookup and assignment. Updating stock changes the entry associated with stock.

Example Output

Keyboard
{'name': 'Keyboard', 'price': 49.9, 'stock': 11}
Maya is 28

A Second Example

Compare this smaller variation with the main example, then experiment with your own values.

person = {"name": "Maya", "age": 28}
print(f"{person['name']} is {person['age']}")

Important Behavior and Edge Cases

Do not blindly assume a key exists in imported data. Use get() or explicit validation when fields are optional.

Try It Yourself

Add a category field and print a short inventory summary.

Common Beginner Mistakes

• Do not blindly assume a key exists in imported data. Use get() or explicit validation when fields are optional.
• Treating missing dictionary keys, replacement precedence, and shallow copies as if they had identical behavior in every context.

Key Takeaways

• A dictionary represents one record as named fields.
• The dictionary uses keys for lookup and assignment.
• Do not blindly assume a key exists in imported data.