Level 1 — RecognitionPython Intermediate

Python Intermediate

⏱ 20 minutes30 marksprintable — key stays hidden on paper

Chapter: 1.3 Python Intermediate Level: 1 — Recognition (MCQ, Matching, True/False with justification) Time Limit: 20 minutes Total Marks: 30

Section A — Multiple Choice (1 mark each, 12 marks)

Choose the single best answer.

Q1. Which statement correctly imports only the sqrt function from the math module?

(a) import sqrt from math
(b) from math import sqrt
(c) import math.sqrt
(d) from math import *sqrt

Q2. What does the file open mode 'a' do?

(a) Opens for reading only
(b) Truncates the file then writes
(c) Opens for appending, writing at the end of the file
(d) Opens a binary file for reading

Q3. Which method reads the entire file and returns a list of lines?

(a) read()
(b) readline()
(c) readlines()
(d) readtext()

Q4. In a decorator, functools.wraps is used to:

(a) Cache the function's return value
(b) Preserve the wrapped function's metadata (__name__, __doc__)
(c) Make the function run faster
(d) Convert a function into a generator

Q5. Which keyword turns an ordinary function into a generator function?

(a) return
(b) async
(c) yield
(d) gen

Q6. Which of these is the base class of most built-in exceptions you would normally catch?

(a) BaseException
(b) Exception
(c) Error
(d) RuntimeWarning

Q7. What does re.findall(r'\d+', 'a12b345') return?

(a) ['1', '2', '3', '4', '5']
(b) ['12', '345']
(c) '12345'
(d) [12, 345]

Q8. The with statement guarantees an object's cleanup by calling which method on exit?

(a) __exit__
(b) __close__
(c) __del__
(d) __leave__

Q9. Which collections type provides a dictionary that remembers insertion order and supports default values on missing keys (default factory)?

(a) OrderedDict
(b) defaultdict
(c) namedtuple
(d) Counter

Q10. Calling next() on an exhausted iterator raises:

(a) IndexError
(b) StopIteration
(c) ValueError
(d) KeyError

Q11. Which command creates a virtual environment named env?

(a) pip install env
(b) python -m venv env
(c) virtualenv --requirements env
(d) python venv env

Q12. The else block of a try statement executes when:

(a) An exception is raised
(b) No exception is raised in the try block
(c) Always, before finally
(d) Only if finally is absent

Section B — Matching (1 mark each, 8 marks)

Match each item in Column X to the correct description in Column Y. Write pairs like Q13→(iii).

Column X	Column Y
Q13. `import numpy as np`	(i) Counts hashable objects
Q14. `itertools.count`	(ii) Immutable timestamp/date object
Q15. `collections.Counter`	(iii) Aliasing an imported module
Q16. `datetime.datetime`	(iv) Infinite arithmetic-step iterator
Q17. `os` module	(v) Interpreter-related info (argv, exit)
Q18. `sys` module	(vi) OS interaction (paths, environ)
Q19. `re.sub`	(vii) Replaces pattern matches with a string
Q20. `functools.reduce`	(viii) Folds an iterable to a single value

Section C — True / False with Justification (2 marks each, 10 marks)

State True or False (1 mark) and give a one-line justification (1 mark).

Q21. A custom exception class must inherit from Exception (directly or indirectly) to be raised with raise.

Q22. Opening a file with mode 'w' on an existing file preserves its previous contents.

Q23. A generator's send(value) resumes the generator, and value becomes the result of the paused yield expression.

Q24. The finally block runs even if a return occurs inside the try block.

Q25. In regex, the parentheses in r'(\d{4})-(\d{2})' create two capturing groups.

Answer keyMark scheme & solutions

Section A (1 mark each)

Q1. (b) — from math import sqrt is the correct from…import syntax; other options are invalid grammar.

Q2. (c) — 'a' = append mode; writes go to end of file, file created if absent, existing content kept.

Q3. (c) — readlines() returns a list of lines; read() returns one string, readline() returns one line.

Q4. (b) — @functools.wraps copies metadata so the wrapper "looks like" the original function.

Q5. (c) — Presence of yield makes a function a generator.

Q6. (b) — Exception is the standard base for catchable exceptions; BaseException also covers SystemExit/KeyboardInterrupt which we usually don't catch.

Q7. (b) — \d+ matches one-or-more digits greedily → ['12', '345']; results are strings, not ints.

Q8. (a) — with calls __enter__ on entry and __exit__ on exit.

Q9. (b) — defaultdict supplies a default via factory on missing keys. (Ordinary dicts already keep insertion order in modern Python; the default factory is the distinguishing feature.)

Q10. (b) — Exhausted iterators raise StopIteration.

Q11. (b) — python -m venv env creates the venv.

Q12. (b) — else runs only when the try block completes without raising.

Section B (1 mark each)

Q13 → (iii) aliasing an imported module
Q14 → (iv) infinite arithmetic-step iterator
Q15 → (i) counts hashable objects
Q16 → (ii) immutable timestamp/date object
Q17 → (vi) OS interaction (paths, environ)
Q18 → (v) interpreter-related info (argv, exit)
Q19 → (vii) replaces pattern matches with a string
Q20 → (viii) folds an iterable to a single value

Section C (2 marks each: 1 verdict + 1 justification)

Q21. True. — raise requires an object whose class derives from BaseException; custom exceptions conventionally subclass Exception. (Full inheritance from BaseException is technically the rule, but subclassing Exception is the standard/expected answer.)

Q22. False. — Mode 'w' truncates the file to zero length, destroying previous contents.

Q23. True. — gen.send(value) resumes execution; the paused yield expression evaluates to value.

Q24. True. — finally always executes, including when try/except contains a return (it runs before the actual return handoff).

Q25. True. — Each (...) is a capturing group; here there are two, capturing the 4-digit and 2-digit segments.

[
  {"claim":"re.findall(r'\\d+','a12b345') == ['12','345']","code":"import re; result = re.findall(r'\\d+','a12b345') == ['12','345']"},
  {"claim":"re pattern (\\d{4})-(\\d{2}) has 2 capturing groups","code":"import re; result = re.compile(r'(\\d{4})-(\\d{2})').groups == 2"},
  {"claim":"defaultdict supplies default via factory on missing key","code":"from collections import defaultdict; d = defaultdict(int); result = d['x'] == 0"},
  {"claim":"generator send delivers value into yield expression","code":"\ndef g():\n    x = yield 1\n    yield x*10\nit = g(); next(it); result = it.send(5) == 50"}
]