Computer Science · Class 9
Python: Data Structures
Learn Python: Data Structures with notes, examples, and practice questions.
3 sections15–25 min read6 MCQs · 2 examples
Chapter Overview
Python: Data Structures covers Python lists, tuples, dictionaries, and stacks/queues — choosing the right structure for efficient data access in Class 9 programs.
Lists and Tuples
- List: ordered, mutable — append, pop, insert, slice
- Tuple: ordered, immutable — used for fixed data
- Indexing from 0; negative index from end
Dictionaries and Stacks
- Dict: {key: value} mapping for fast lookup
- Stack: LIFO using list append/pop
- Queue: FIFO using collections.deque
Solved Examples
Step-by-step solutions — read each step before checking the final answer.
List operations
lst = [10, 20, 30]. Find lst[1] after append(40).
- 1lst[1] = 20
- 2After append: [10, 20, 30, 40]
Answer
20; [10, 20, 30, 40]
Dictionary access
d = {'a': 1, 'b': 2}. Value of d['b']?
- 1Access by key 'b'
- 2d['b'] = 2
Answer
2
Key Points to Remember
- ✓ Lists mutable; tuples immutable
- ✓ Dict keys must be immutable types
- ✓ Stack pop removes last element (LIFO)
Exam Tips
- • Trace list methods step by step
- • Know mutable vs immutable
- • Write stack push/pop example
Practice MCQs — Python: Data Structures
Test your understanding with topic-wise multiple choice questions. Explanations appear after each answer.
Question 1 of 6Score: 0/0
Which is mutable?