POC Performance Optimization 2

Question 1

Which Python built-in function returns an iterator over a range of numbers without creating a list in memory?

Accepted Answer

range()

Answer

range() in Python 3 returns a lazy iterator that generates numbers on demand, avoiding memory allocation for the full sequence.

Question 2

What is the primary advantage of using `array` module over a list for numeric data in Python?

Accepted Answer

Lower memory usage due to typed storage

Answer

The array module stores elements as typed C values, consuming significantly less memory than Python lists which store object references.

Question 3

Which caching strategy does `functools.lru_cache` implement?

Accepted Answer

Least Recently Used (LRU)

Answer

lru_cache evicts the least recently used entries when the cache reaches its maximum size, keeping frequently accessed results.

Question 4

What does the `__slots__` class attribute do in Python?

Accepted Answer

Replaces the instance __dict__ to reduce memory overhead

Answer

__slots__ eliminates the per-instance __dict__, reducing memory usage significantly when creating many instances of a class.

Question 5

Which of the following is the fastest way to concatenate many strings in Python?

Accepted Answer

Using ''.join(list_of_strings)

Answer

''.join() is O(n) because it allocates one buffer for all strings, while += in a loop creates a new string object on every iteration.

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