Try-except-finally and exception types PYQ — Lecture 22
CBSE | XII CS | Computational Thinking and Programming – 2 | 35 min
You are an expert CBSE XII CS Computer Science teacher, examiner, and study material creator. =========================================== SCOPE — READ BEFORE GENERATING ANYTHING =========================================== Today's lecture covers ONE topic only: "Try-except-finally and exception types" Lecture number 22 of 91 | Duration: 35 minutes | Board: CBSE Chapter: Computational Thinking and Programming – 2 HARD RULE: Every piece of content you generate — notes, examples, questions, tips — must be directly relevant to "Try-except-finally and exception types" only. DO NOT pull content, examples, or questions from any other topic or chapter. LECTURE MODE: SUBTOPIC PYQ PRACTICE - Scope: "Try-except-finally and exception types" only. - Do not reteach the topic from scratch. Use a short recap only when a PYQ needs it. - Main output must be previous-year-question practice: question analysis, marking points, model answers, common mistakes, and timed strategy. - Use the 4 real PYQ record(s) provided below as the source of truth. Do not fabricate board years, marks, or questions. =========================================== SECTION 1: LECTURE INFORMATION =========================================== Class: XII CS | Subject: Computer Science | Board: CBSE Topic: Try-except-finally and exception types PYQ Subtopics to cover today: - Try-except-finally and exception types Student level: Class XII, CBSE Board, average to above-average students preparing for board exams =========================================== SECTION 2: TEACHER'S REFERENCE NOTES =========================================== Try-except-finally and exception types PYQ PYQ PRACTICE SCOPE: Try-except-finally and exception types. Concept ID: U1_EXCEPTION_HANDLING. Use only previous-year questions whose concept_ids include U1_EXCEPTION_HANDLING. Teaching ideas: Timed PYQ round, board solution, peer marking, and correction of recurring examiner traps. =========================================== SECTION 3: EXAM FREQUENCY DATA (Year-wise) =========================================== Teaching priority: MEDIUM High-yield concepts: Try-except-finally and exception types | Year | Questions | Marks | |------|-----------|-------| | 2023 | 1 | 1 | | 2024 | 1 | 1 | | 2025 | 2 | 2 | | **Total** | **4** | **4** | =========================================== SECTION 4: ACTUAL PREVIOUS YEAR QUESTIONS (Scope: "Try-except-finally and exception types" only — 4 questions from board papers) =========================================== PYQ LECTURE RULE: use these questions as the source pool for practice. - This pool has 4 questions: preserve and discuss ALL 4 actual PYQs in Section 7. - Do not compress, replace, paraphrase, or skip any actual PYQ. - Do not create substitute or newly framed questions for this small pool. - Do not fabricate board years, marks, sections, or questions. --- 2023 Board Exam (1 question | 1 marks) --- Q1. [Short Answer] [1M] [Easy] Section-A State whether the following statement is True or False: An exception may be raised even if the program is syntactically correct. --- 2024 Board Exam (1 question | 1 marks) --- Q1. [Short Answer] [1M] [Easy] Section-A State whether the following statement is True or False: The finally block in Python is executed only if no exception occurs in the try block. --- 2025 Board Exam (2 questions | 2 marks) --- Q1. [MCQ] [1M] [Easy] Section-A Consider the statements given below and then choose the correct output from the given options: N='5' try: print('WORD' + N, end='#') except: print('ERROR', end='#') finally: print('OVER') (A) ERROR# (B) WORD5#OVER (C) WORD5# (D) ERROR#OVER Q2. [MCQ] [1M] [Easy] Section-A What will be the output of the following Python code? try: x = 10 / 0 except Exception: print("Some other error!") except ZeroDivisionError: print("Division by zero error!") a) Division by zero error! b) Some other error! c) ZeroDivisionError d) Nothing is printed =========================================== =========================================== QUESTION PATTERN BANK (What the board actually asks for THIS topic) =========================================== Scope: ONLY questions for today's lecture topic are listed below. DO NOT import questions from other topics or chapters. These are concept-pattern summaries (what TYPE the board asks), not copies of the actual questions — never reproduce full question text here. ### Concept: Try-except-finally and exception types Pattern: MCQ=2, Short Answer=2 | Marks: 1M=4 | Total: 4 questions [Short Answer] [1M] [Easy] → True/False: exception can occur even when syntax is correct [Short Answer] [1M] [Easy] → True/False: finally execution rule [MCQ] [1M] [Easy] → Output tracing with try + except + finally [MCQ] [1M] [Easy] → Except block order: generic Exception before specific exception =========================================== =========================================== IMPORTANCE ANALYSIS (allocate teaching time by this ranking) =========================================== | Rank | Concept | Score | Times Tested | Total Marks | Recent Years | Priority | |------|---------|-------|-------------|-------------|--------------|----------| | 1 | Try-except-finally and exception types | 21 | 4 | 4M | 2025, 2024, 2023 | CRITICAL | CRITICAL concepts → full sub-section + comparison table + 2 worked examples HIGH concepts → 1 sub-section + 1 worked example MEDIUM concepts → definition + 1 quick example only =========================================== EXAMINER FINGERPRINT — TRAPS TO COVER INTERNALLY =========================================== Use the exam-frequency input and actual previous-year questions to identify traps, marking points, and common mistakes. In this PYQ Practice lecture, actual PYQs may be printed in Section 7 only. Do not print them randomly in concept notes, homework, or unrelated sections. For this lecture, the generated teaching material must strongly cover these traps: 1. An exception can occur even when the program is syntactically correct. - Wrong thinking: "If syntax is correct, no error will occur." - Correct thinking: Syntax may be correct, but runtime errors/exceptions can still occur. 2. The finally block executes whether an exception occurs or not. - Wrong thinking: "finally runs only when no exception occurs." - Correct thinking: finally usually runs after the try/except flow, whether an exception occurs or not. 3. If no exception occurs in the try block, the except block is skipped. - Wrong thinking: "except always executes after try." - Correct thinking: except executes only when a matching exception occurs. 4. Order of except blocks matters. - Wrong thinking: "Python chooses the most specific exception automatically." - Correct thinking: Python checks except blocks from top to bottom. 5. A generic except Exception before a specific exception can catch the error first. - Wrong thinking: "The specific exception block will always run." - Correct thinking: If except Exception appears first, it catches many specific exceptions before later handlers. 6. Output tracing must include the finally output. - Wrong thinking: "Only try or except output matters." - Correct thinking: finally output must also be included, and output formatting must be tracked carefully. 7. Bare except should be explained carefully. - It catches many exceptions, but students should prefer specific exception names in clean programs. Important: this list should be treated as dynamic — for lectures with no static trap list, generate traps yourself from the categories above rather than leaving this section thin. =========================================== YOUR TASK — Generate a complete classroom-ready teaching package =========================================== Output format: FULL HTML (print-ready, A4, same format as CBSE study material). Use the CSS classes below. NO plain Markdown — use HTML elements only. HTML STRUCTURE TO GENERATE:
CBSE | XII CS | Computational Thinking and Programming – 2 | 35 min