Give a value a name you can look up.

Use a dictionary to keep related details in one small record.

2 min read 5 min to try

MAKE ROOM FORoneSMALL SKILL

A label can be more useful than a position.

Suppose you are describing a book. A list containing a title, a page count, and a reading status requires you to remember which position means what. A dictionary lets you attach a key to each value.

In the example, title and pages are keys. The values are “Small Adventures” and 96. Square brackets look up a value using its key. The quotation marks matter: "title" is text, while title without quotes would be a variable name.

A named lookup

Record

title → Small Adventures pages → 96

Optional lookup

author → Not listed

The fallback describes a missing field, not a fact about the author.

Decide what should happen when a detail is absent.

Looking up a missing key with square brackets raises a KeyError. For optional details, get() lets you provide a fallback. Here, an absent author becomes “Not listed” instead of stopping the program.

Choose a fallback that tells the truth. “Not listed” means this record does not contain the detail; it does not mean the book has no author. Small wording choices help your program preserve the difference between absent data and a real value.

A small example to try

book = {"title": "Small Adventures", "pages": 96}
print(book["title"])
print(book.get("author", "Not listed"))

Your turn 5 minutes

Make it yours.

Run the example and read the two lines.
Add an author key with a fictional name.
Run it again and notice which output changes.

What changed when you tried it?

A little nudge

Place a comma between key-value pairs inside the braces.

What to look for

The first run prints Small Adventures and Not listed. After adding author, the second line contains your chosen name.

Take it one small step further

Change the page count and print book["pages"].

Keep this bit

Use named keys when the meaning matters more than the position.