Is the enumerate, zip, range lesson free?

The interactive enumerate, zip, range 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 enumerate, zip, range 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 enumerate, zip, range 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 enumerate, zip, range lesson?

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

enumerate, zip, range

Beginner
6 min
Fundamentals
basics · iteration
Try it

Lesson 12 of 43

In this track

You’ll be able to

Iterate with enumerate() for indexed loops
Loop over multiple sequences in parallel with zip()
Reverse iteration with reversed()
Sort iterables by custom keys with sorted(..., key=...)

Why this matters

enumerate and zip are the mark of Pythonic code; reviewers flag for i in range(len(x)) on sight. dict.items() shows up in every config loader, template renderer, and ORM serializer in the ecosystem.

Common pitfalls

Writing for i in range(len(lst)): lst[i] instead of enumerate(lst). It works but reads as non-Pythonic in code review.
Assuming zip errors on unequal lengths. It silently truncates; use zip(a, b, strict=True) on Python 3.10+ to catch mismatches.
Calling .items() and unpacking wrong: for k, v in d.items() is correct; for k in d.items() gives you tuples.

Beginner · 5 minTruthiness & NoneEmpty things are False. `is` vs `==`. The infamous None.Beginner · 8 minFunctionsBundle up logic so you can reuse it.Beginner · 6 minDictionariesKey → value pairs. The most important data structure in Python.

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You’ll be able to

Iterate with enumerate() for indexed loops
Loop over multiple sequences in parallel with zip()
Reverse iteration with reversed()
Sort iterables by custom keys with sorted(..., key=...)

Why this matters

Common pitfalls

Writing for i in range(len(lst)): lst[i] instead of enumerate(lst). It works but reads as non-Pythonic in code review.
Assuming zip errors on unequal lengths. It silently truncates; use zip(a, b, strict=True) on Python 3.10+ to catch mismatches.
Calling .items() and unpacking wrong: for k, v in d.items() is correct; for k in d.items() gives you tuples.

You’ll be able to

Why this matters

Common pitfalls

Related lessons

You’ll be able to

Why this matters

Common pitfalls

Related lessons