Is the Dictionaries lesson free?

The interactive Dictionaries lesson is part of Pro (₹299/month). The first 5 lessons of the track are free — no account or card needed.

How long does the Dictionaries lesson take?

About 6 minutes end-to-end. It's a hands-on lesson — you read a paragraph, edit the code, and run it in the same tab.

Do I need to install Python to try the Dictionaries lesson?

No install required. PyRun runs real CPython in your browser via Pyodide (Python compiled to WebAssembly). Works on Chrome, Firefox, Safari, and Edge — desktop or mobile.

What level is the Dictionaries lesson?

Beginner level. No prior Python required — good starting point.

Dictionaries

Beginner
6 min
Fundamentals
basics · dicts
Try it

Lesson 10 of 43

In this track

You’ll be able to

Store key-value pairs with dict literals {}
Look up, update, and delete entries safely
Iterate over keys, values, and items with .keys(), .values(), .items()
Use .get() to avoid KeyError when accessing missing keys

Why this matters

Dicts back every JSON API response, Django ORM row, and pandas record. Redis, MongoDB, and even Python's own class attributes are dicts under the hood. Fluency here is non-negotiable for backend or data roles.

Common pitfalls

Accessing a missing key with d[k] raises KeyError. Use d.get(k) or d.get(k, default) for safe lookups.
Using mutable objects like lists as keys. Only hashable types (str, int, tuple) work; lists raise TypeError.
Iterating for k in d and expecting values. That yields keys; use d.items() for pairs.

Beginner · 6 minTuples & SetsTwo more collections: tuples are fixed, sets are unique.Beginner · 5 minTruthiness & NoneEmpty things are False. `is` vs `==`. The infamous None.Beginner · 5 minSlicingCarve up lists and strings with [start:stop:step].

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You’ll be able to

Store key-value pairs with dict literals {}
Look up, update, and delete entries safely
Iterate over keys, values, and items with .keys(), .values(), .items()
Use .get() to avoid KeyError when accessing missing keys

Why this matters

Common pitfalls

Accessing a missing key with d[k] raises KeyError. Use d.get(k) or d.get(k, default) for safe lookups.
Using mutable objects like lists as keys. Only hashable types (str, int, tuple) work; lists raise TypeError.
Iterating for k in d and expecting values. That yields keys; use d.items() for pairs.

You’ll be able to

Why this matters

Common pitfalls

Related lessons

You’ll be able to

Why this matters

Common pitfalls

Related lessons