Data Science & Machine Learning
The first channel on Telegram that offers exciting questions, answers, and tests in data science, artificial intelligence, machine learning, and programming languages. For promotions: @love_data
Show more📈 Analytical overview of Telegram channel Data Science & Machine Learning
Channel Data Science & Machine Learning (@datascienceinterviews) in the English language segment is an active participant. Currently, the community unites 27 224 subscribers, ranking 7 207 in the Education category and 16 012 in the India region.
📊 Audience metrics and dynamics
Since its creation on невідомо, the project has demonstrated rapid growth, gathering an audience of 27 224 subscribers.
According to the latest data from 11 June, 2026, the channel demonstrates stable activity. Although there has been a change in the number of participants by 90 over the last 30 days and by -3 over the last 24 hours, overall reach remains high.
- Verification status: Not verified
- Engagement rate (ER): The average audience engagement rate is 0.71%. Within the first 24 hours after publication, content typically collects 0.62% reactions from the total number of subscribers.
- Post reach: On average, each post receives 192 views. Within the first day, a publication typically gains 169 views.
- Reactions and interaction: The audience actively supports content: the average number of reactions per post is 1.
- Thematic interests: Content is focused on key topics such as insidead, mining, pinix, learning, neo.
📝 Description and content policy
The author describes the resource as a platform for expressing subjective opinions:
“The first channel on Telegram that offers exciting questions, answers, and tests in data science, artificial intelligence, machine learning, and programming languages.
For promotions: @love_data”
Thanks to the high frequency of updates (latest data received on 12 June, 2026), the channel maintains relevance and a high level of publication reach. Analytics show that the audience actively interacts with content, making it an important point of influence in the Education category.
def add_item(item, lst=None):
if lst is None:
lst = []
lst.append(item)
return lst
print(add_item(1))
print(add_item(2))
A. [1] then [2]
B. [1] then [1, 2]
C. [] then []
D. Raises TypeError
Correct answer: A.
2. What is printed by this code?
x = 10
def func():
print(x)
x = 5
func()
A. 10
B. 5
C. None
D. UnboundLocalError
Correct answer: D.
3. What is the result of executing this code?
a = [1, 2, 3]
b = a[:]
a.append(4)
print(b)
A. [1, 2, 3, 4]
B. [4]
C. [1, 2, 3]
D. []
Correct answer: C.
4. What does the following expression evaluate to?
bool("False")
A. False
B. True
C. Raises ValueError
D. None
Correct answer: B.
5. What will be the output?
print(type({}))
A. <class 'list'>
B. <class 'set'>
C. <class 'dict'>
D. <class 'tuple'>
Correct answer: C.
6. What is printed by this code?
x = (1, 2, [3])
x[2] += [4]
print(x)
A. (1, 2, [3])
B. (1, 2, [3, 4])
C. TypeError
D. AttributeError
Correct answer: C.
7. What does this code output?
print([i for i in range(3) if i])
A. [0, 1, 2]
B. [1, 2]
C. [0]
D. []
Correct answer: B.
8. What will be printed?
d = {"a": 1}
print(d.get("b", 2))
A. None
B. KeyError
C. 2
D. "b"
Correct answer: C.
9. What is the output?
print(1 in [1, 2], 1 is 1)
A. True True
B. True False
C. False True
D. False False
Correct answer: A.
10. What does this code produce?
def gen():
for i in range(2):
yield i
g = gen()
print(next(g), next(g))
A. 0 1
B. 1 2
C. 0 0
D. StopIteration
Correct answer: A.
11. What is printed?
print({x: x*x for x in range(2)})
A. {0, 1}
B. {0: 0, 1: 1}
C. [(0,0),(1,1)]
D. Error
Correct answer: B.
12. What is the result of this comparison?
print([] == [], [] is [])
A. True True
B. False False
C. True False
D. False True
Correct answer: C.
13. What will be printed?
def f():
try:
return "A"
finally:
print("B")
print(f())
A. A
B. B
C. B then A
D. A then B
Correct answer: C.
14. What does this code output?
x = [1, 2]
y = x
x = x + [3]
print(y)
A. [1, 2, 3]
B. [3]
C. [1, 2]
D. Error
Correct answer: C.
15. What is printed?
print(type(i for i in range(3)))
A. <class 'list'>
B. <class 'tuple'>
C. <class 'generator'>
D. <class 'range'>
Correct answer: C.return to yield multiple values
C. They produce values lazily using yield
D. They cannot be iterated over
Correct answer: C.
4. What does the __slots__ attribute primarily optimize?
A. Method resolution order
B. Attribute access speed and memory usage
C. Garbage collection
D. Inheritance depth
Correct answer: B.
5. Which data structure guarantees insertion order preservation as of Python 3.7?
A. set
B. tuple
C. dict
D. frozenset
Correct answer: C.
6. What is the main advantage of using collections.defaultdict?
A. Faster sorting
B. Automatic key initialization
C. Reduced memory footprint
D. Immutable values
Correct answer: B.
7. Which statement about list comprehensions is correct?
A. They always execute faster than loops
B. They cannot contain conditions
C. They create lists eagerly
D. They are equivalent to generators
Correct answer: C.
8. What does the * operator do in function parameters?
A. Forces keyword-only arguments
B. Captures extra positional arguments
C. Unpacks dictionaries
D. Captures extra keyword arguments
Correct answer: B.
9. What is the role of **kwargs in a function definition?
A. Enforce positional arguments
B. Capture extra keyword arguments
C. Define default values
D. Improve performance
Correct answer: B.
10. Which protocol enables objects to be used in for loops?
A. Context manager protocol
B. Descriptor protocol
C. Iterator protocol
D. Numeric protocol
Correct answer: C.
11. What must an object implement to be an iterator?
A. __iter__ only
B. __next__ only
C. Both __iter__ and __next__
D. __getitem__
Correct answer: C.
12. What is the primary use of context managers?
A. Memory allocation
B. Automatic resource management
C. Error suppression
D. Parallel execution
Correct answer: B.
13. Which keyword is used to define a context manager without a class?
A. with
B. manage
C. using
D. yield
Correct answer: D.
14. What problem does the Global Interpreter Lock (GIL) primarily affect?
A. File I/O performance
B. Network latency
C. CPU-bound multithreaded code
D. Memory leaks
Correct answer: C.
15. Which module is commonly used for parallelism that bypasses the GIL?
A. threading
B. asyncio
C. multiprocessing
D. concurrent.futures.thread
Correct answer: C.
16. What distinguishes asyncio from threading?
A. It uses OS-level threads
B. It is based on cooperative multitasking
C. It bypasses the GIL
D. It is suitable only for CPU-bound tasks
Correct answer: B.
17. What does the await keyword do?
A. Blocks the entire program
B. Pauses execution until a coroutine completes
C. Starts a new thread
D. Forces synchronous execution
Correct answer: B.
18. Which operation is typically CPU-bound?
A. Reading a file
B. Waiting for a network response
C. Parsing a large dataset
D. Sleeping for one second
Correct answer: C.
19. What is the main benefit of using functools.lru_cache?
A. Improves recursion depth
B. Memoizes function results
C. Reduces function arguments
D. Enables parallel execution
Correct answer: B.
20. Which statement about Python exceptions is correct?
A. They always terminate the program
B. They cannot be nested
C. They propagate up the call stack if unhandled
D. They are only for runtime errors
Correct answer: C.def f(x, l=[]):
l.append(x)
return l
print(f(1))
print(f(2))
A. [1] then [2]
B. [1] then [1, 2]
C. Error due to mutable default
D. [] then []
Correct answer: B.
2. What is the result of this expression?
a = [1, 2, 3]
b = a
a += [4]
A. a = [1,2,3], b = [1,2,3]
B. a = [1,2,3,4], b = [1,2,3]
C. a = [1,2,3,4], b = [1,2,3,4]
D. Raises TypeError
Correct answer: C.
3. What does this code print?
print(bool([]), bool({}), bool(()))
A. True True True
B. False False False
C. False True False
D. True False True
Correct answer: B.
4. What is the output?
x = 10
def outer():
x = 20
def inner():
nonlocal x
x += 5
inner()
return x
print(outer())
A. 10
B. 20
C. 25
D. UnboundLocalError
Correct answer: C.
5. What happens when this code is executed?
class A:
def __init__(self):
self.x = 1
a = A()
a.__dict__['x'] = 2
print(a.x)
A. 1
B. 2
C. AttributeError
D. KeyError
Correct answer: B.
6. What is printed?
print([i for i in range(3)] is [i for i in range(3)])
A. True
B. False
C. SyntaxError
D. Depends on Python version
Correct answer: B.
7. What does this code output?
def gen():
yield from range(3)
print(list(gen()))
A. [0, 1, 2]
B. [1, 2, 3]
C. range(0, 3)
D. Error
Correct answer: A.
8. What is the result?
a = (1, 2, [3, 4])
a[2].append(5)
print(a)
A. Error: tuple is immutable
B. (1, 2, [3, 4])
C. (1, 2, [3, 4, 5])
D. (1, 2, 5)
Correct answer: C.
9. What does this print?
print({i: i*i for i in range(3)})
A. {0, 1, 4}
B. {0: 0, 1: 1, 2: 4}
C. [(0,0),(1,1),(2,4)]
D. Error
Correct answer: B.
10. What is the output?
print(type(lambda x: x))
A. <class 'function'>
B. <class 'lambda'>
C. <class 'callable'>
D. <class 'object'>
Correct answer: A.
11. What happens here?
try:
1 / 0
finally:
print("done")
A. Nothing is printed
B. ZeroDivisionError only
C. Prints "done" then raises ZeroDivisionError
D. Prints "done" only
Correct answer: C.
12. What is printed?
x = [1, 2, 3]
print(x[::-1] is x)
A. True
B. False
C. Error
D. Depends on interpreter
Correct answer: B.
13. What does this code demonstrate?
class A: pass
class B(A): pass
print(issubclass(B, A))
A. Duck typing
B. Multiple inheritance
C. Polymorphism
D. Inheritance
Correct answer: D.
14. What is the output?
print(all([0, 1, 2]), any([0, 1, 2]))
A. True True
B. False True
C. True False
D. False False
Correct answer: B.
15. What will this print?
x = 5
def f():
print(x)
x = 3
f()
A. 5
B. 3
C. UnboundLocalError
D. NameError
Correct answer: C.
16. What is the result?
a = {1, 2, 3}
b = {3, 2, 1}
print(a == b)
A. False
B. True
C. TypeError
D. Order dependent
Correct answer: B.
17. What does this output?
print(type((i for i in range(3))))
A. <class 'list'>
B. <class 'tuple'>
C. <class 'generator'>
D. <class 'iterator'>
Correct answer: C.
18. What is printed?
x = [1, 2, 3]
y = x.copy()
x.append(4)
print(y)
A. [1,2,3,4]
B. [4]
C. [1,2,3]
D. Error
Correct answer: C.
19. What does this evaluate to?
print(1 == True, 0 == False)
A. False False
B. True True
C. True False
D. False True
Correct answer: B.
20. What is the output?
def f():
try:
return 1
finally:
return 2
print(f())
A. 1
B. 2
C. None
D. RuntimeError
Correct answer: B.
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