Cheat sheet · Class 11 · CBSE · Science Computer Science
Tuples and Dictionaries cheat sheet
The whole chapter on one page: key formulas, facts and the points to remember, for quick revision before a test.
CBSE Class 11 · Computer Science
Cheat sheet
Chapter 10Tuples and Dictionaries
Tuple: fixed record. Dictionary: key → value lookup.
1. Tuples
- Immutable sequences: (1, 2, 3).
- Single element needs a comma: (5,).
- Packing/unpacking: a, b = b, a swaps.
- Methods: count(), index(); functions: len, min, max, sum, sorted.
2. Dictionaries
- Unordered (insertion-ordered in 3.7+) key: value pairs.
- Keys must be immutable and unique.
- d[key] = value adds or updates.
3. Dictionary Methods
| Method | Does |
|---|---|
| keys(), values(), items() | views of keys, values, pairs |
| get(k, default) | value or default (no error) |
| update(d2) | merge another dict |
| pop(k), popitem(), clear() | remove items |
| del d[k] | delete a key |
| fromkeys(), copy(), setdefault() | build / copy / default |
Count characters: for ch in s: d[ch] = d.get(ch, 0) + 1
4. Key Points
- Tuple can be a dict key; list cannot.
- Membership on a dict checks keys.
- Tuples are faster than lists.
- dict() can be built from a list of pairs.
Remember: Tuple immutable | (5,) | dict methods | get() default
Tuples and Dictionaries: questions and notes
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