Practice Python Performance MCQ questions with detailed explanations and clear answer validation. These MCQs help you revise core concepts, compare close options, and improve accuracy for interviews, certification exams, and technical screening rounds. Use this updated 2026 set to strengthen fundamentals and confidence.
Q51. Which statement about avoiding global lookups is most accurate?
Select an answer to check.
Answer: Bind to locals in hot loops.
Here, Bind to locals in hot loops. is the right choice. Local var access is faster. It aligns directly with what the question asks about which statement about avoiding global lookups is most. Competing choices sound plausible, but they miss the key condition.
Q52. How is avoiding global lookups best characterized?
Select an answer to check.
Answer: Bind to locals in hot loops.
In this case, Bind to locals in hot loops. is correct. Local var access is faster. It aligns directly with what the question asks about how is avoiding global lookups best characterized. Competing choices sound plausible, but they miss the key condition.
Q53. Which option best describes list vs generator?
Select an answer to check.
Answer: Lists materialize; generators stream.
The best option here is Lists materialize; generators stream.. Generators save memory. It aligns directly with what the question asks about which option best describes list vs generator. Competing choices sound plausible, but they miss the key condition.
Q54. What is the primary purpose of list vs generator?
Select an answer to check.
Answer: Lists materialize; generators stream.
For this question, Lists materialize; generators stream. is correct. Generators save memory. It aligns directly with what the question asks about what is the primary purpose of list vs. Competing choices sound plausible, but they miss the key condition.
Q55. Which statement about list vs generator is most accurate?
Select an answer to check.
Answer: Lists materialize; generators stream.
Lists materialize; generators stream. is the correct answer here. Generators save memory. It aligns directly with what the question asks about which statement about list vs generator is most. Competing choices sound plausible, but they miss the key condition.
Q56. How is list vs generator best characterized?
Select an answer to check.
Answer: Lists materialize; generators stream.
Here, Lists materialize; generators stream. is the right choice. Generators save memory. This matches the core idea being tested around how is list vs generator best characterized. Competing choices sound plausible, but they miss the key condition.
Q57. Which option best describes slots?
Select an answer to check.
Answer: __slots__ avoids per-instance dict.
In this case, __slots__ avoids per-instance dict. is correct. Saves memory for many instances. This matches the core idea being tested around which option best describes slots. Competing choices sound plausible, but they miss the key condition.
Q58. What is the primary purpose of slots?
Select an answer to check.
Answer: __slots__ avoids per-instance dict.
The best option here is __slots__ avoids per-instance dict.. Saves memory for many instances. This matches the core idea being tested around what is the primary purpose of slots. Competing choices sound plausible, but they miss the key condition.
Q59. Which statement about slots is most accurate?
Select an answer to check.
Answer: __slots__ avoids per-instance dict.
For this question, __slots__ avoids per-instance dict. is correct. Saves memory for many instances. This matches the core idea being tested around which statement about slots is most accurate. Competing choices sound plausible, but they miss the key condition.
Q60. How is slots best characterized?
Select an answer to check.
Answer: __slots__ avoids per-instance dict.
__slots__ avoids per-instance dict. is the correct answer here. Saves memory for many instances. This matches the core idea being tested around how is slots best characterized. Competing choices sound plausible, but they miss the key condition.
Here, Reuse identical immutables (small ints, strings). is the right choice. Reduces memory. That is exactly the concept behind which option best describes interning in this context. Competing choices sound plausible, but they miss the key condition.
In this case, Reuse identical immutables (small ints, strings). is correct. Reduces memory. That is exactly the concept behind what is the primary purpose of interning in this context. Competing choices sound plausible, but they miss the key condition.
Q63. Which statement about interning is most accurate?
The best option here is Reuse identical immutables (small ints, strings).. Reduces memory. That is exactly the concept behind which statement about interning is most accurate in this context. Competing choices sound plausible, but they miss the key condition.
For this question, Reuse identical immutables (small ints, strings). is correct. Reduces memory. That is exactly the concept behind how is interning best characterized in this context. Competing choices sound plausible, but they miss the key condition.
Q65. Which option best describes string concatenation?
Select an answer to check.
Answer: Use ''.join for many parts.
Use ''.join for many parts. is the correct answer here. + in loop is O(n^2). That is exactly the concept behind which option best describes string concatenation in this context. Competing choices sound plausible, but they miss the key condition.
Q66. What is the primary purpose of string concatenation?
Select an answer to check.
Answer: Use ''.join for many parts.
Here, Use ''.join for many parts. is the right choice. + in loop is O(n^2). It fits the requirement in the prompt about what is the primary purpose of string concatenation. Competing choices sound plausible, but they miss the key condition.
Q67. Which statement about string concatenation is most accurate?
Select an answer to check.
Answer: Use ''.join for many parts.
In this case, Use ''.join for many parts. is correct. + in loop is O(n^2). It fits the requirement in the prompt about which statement about string concatenation is most accurate. Competing choices sound plausible, but they miss the key condition.
Q68. How is string concatenation best characterized?
Select an answer to check.
Answer: Use ''.join for many parts.
The best option here is Use ''.join for many parts.. + in loop is O(n^2). It fits the requirement in the prompt about how is string concatenation best characterized. Competing choices sound plausible, but they miss the key condition.
Q69. Which option best describes dict access?
Select an answer to check.
Answer: O(1) average lookup.
For this question, O(1) average lookup. is correct. Hash tables. It fits the requirement in the prompt about which option best describes dict access. Competing choices sound plausible, but they miss the key condition.
Q70. What is the primary purpose of dict access?
Select an answer to check.
Answer: O(1) average lookup.
O(1) average lookup. is the correct answer here. Hash tables. It fits the requirement in the prompt about what is the primary purpose of dict access. Competing choices sound plausible, but they miss the key condition.
Q71. Which statement about dict access is most accurate?
Select an answer to check.
Answer: O(1) average lookup.
Here, O(1) average lookup. is the right choice. Hash tables. This is the most accurate statement for which statement about dict access is most accurate. Competing choices sound plausible, but they miss the key condition.
Q72. How is dict access best characterized?
Select an answer to check.
Answer: O(1) average lookup.
In this case, O(1) average lookup. is correct. Hash tables. This is the most accurate statement for how is dict access best characterized. Competing choices sound plausible, but they miss the key condition.
Q73. Which option best describes set operations?
Select an answer to check.
Answer: O(1) avg add/remove/contains.
The best option here is O(1) avg add/remove/contains.. Use for membership tests. This is the most accurate statement for which option best describes set operations. Competing choices sound plausible, but they miss the key condition.
Q74. What is the primary purpose of set operations?
Select an answer to check.
Answer: O(1) avg add/remove/contains.
For this question, O(1) avg add/remove/contains. is correct. Use for membership tests. This is the most accurate statement for what is the primary purpose of set operations. Competing choices sound plausible, but they miss the key condition.
Q75. Which statement about set operations is most accurate?
Select an answer to check.
Answer: O(1) avg add/remove/contains.
O(1) avg add/remove/contains. is the correct answer here. Use for membership tests. This is the most accurate statement for which statement about set operations is most accurate. Competing choices sound plausible, but they miss the key condition.
Q76. How is set operations best characterized?
Select an answer to check.
Answer: O(1) avg add/remove/contains.
Here, O(1) avg add/remove/contains. is the right choice. Use for membership tests. It aligns directly with what the question asks about how is set operations best characterized. The remaining choices fail because they don’t satisfy the full definition.
Q77. Which option best describes CPU-bound vs I/O-bound?
Select an answer to check.
Answer: Use multiprocessing vs threading/asyncio.
In this case, Use multiprocessing vs threading/asyncio. is correct. Match tool to workload. It aligns directly with what the question asks about which option best describes cpu-bound vs i/o-bound. The remaining choices fail because they don’t satisfy the full definition.
Q78. What is the primary purpose of CPU-bound vs I/O-bound?
Select an answer to check.
Answer: Use multiprocessing vs threading/asyncio.
The best option here is Use multiprocessing vs threading/asyncio.. Match tool to workload. It aligns directly with what the question asks about what is the primary purpose of cpu-bound vs. The remaining choices fail because they don’t satisfy the full definition.
Q79. Which statement about CPU-bound vs I/O-bound is most accurate?
Select an answer to check.
Answer: Use multiprocessing vs threading/asyncio.
For this question, Use multiprocessing vs threading/asyncio. is correct. Match tool to workload. It aligns directly with what the question asks about which statement about cpu-bound vs i/o-bound is most. The remaining choices fail because they don’t satisfy the full definition.
Q80. How is CPU-bound vs I/O-bound best characterized?
Select an answer to check.
Answer: Use multiprocessing vs threading/asyncio.
Use multiprocessing vs threading/asyncio. is the correct answer here. Match tool to workload. It aligns directly with what the question asks about how is cpu-bound vs i/o-bound best characterized. The remaining choices fail because they don’t satisfy the full definition.
Q81. Which option best describes C extensions?
Select an answer to check.
Answer: Move hot code to C/C++/Rust.
Here, Move hot code to C/C++/Rust. is the right choice. Used by NumPy, pandas, etc. This matches the core idea being tested around which option best describes c extensions. The remaining choices fail because they don’t satisfy the full definition.
Q82. What is the primary purpose of C extensions?
Select an answer to check.
Answer: Move hot code to C/C++/Rust.
In this case, Move hot code to C/C++/Rust. is correct. Used by NumPy, pandas, etc. This matches the core idea being tested around what is the primary purpose of c extensions. The remaining choices fail because they don’t satisfy the full definition.
Q83. Which statement about C extensions is most accurate?
Select an answer to check.
Answer: Move hot code to C/C++/Rust.
The best option here is Move hot code to C/C++/Rust.. Used by NumPy, pandas, etc. This matches the core idea being tested around which statement about c extensions is most accurate. The remaining choices fail because they don’t satisfy the full definition.
Q84. How is C extensions best characterized?
Select an answer to check.
Answer: Move hot code to C/C++/Rust.
For this question, Move hot code to C/C++/Rust. is correct. Used by NumPy, pandas, etc. This matches the core idea being tested around how is c extensions best characterized. The remaining choices fail because they don’t satisfy the full definition.
Q85. Which option best describes memoryview?
Select an answer to check.
Answer: Avoid copies on bytes-like objects.
Avoid copies on bytes-like objects. is the correct answer here. Zero-copy buffer access. This matches the core idea being tested around which option best describes memoryview. The remaining choices fail because they don’t satisfy the full definition.
Q86. What is the primary purpose of memoryview?
Select an answer to check.
Answer: Avoid copies on bytes-like objects.
Here, Avoid copies on bytes-like objects. is the right choice. Zero-copy buffer access. That is exactly the concept behind what is the primary purpose of memoryview in this context. The remaining choices fail because they don’t satisfy the full definition.
Q87. Which statement about memoryview is most accurate?
Select an answer to check.
Answer: Avoid copies on bytes-like objects.
In this case, Avoid copies on bytes-like objects. is correct. Zero-copy buffer access. That is exactly the concept behind which statement about memoryview is most accurate in this context. The remaining choices fail because they don’t satisfy the full definition.
Q88. How is memoryview best characterized?
Select an answer to check.
Answer: Avoid copies on bytes-like objects.
The best option here is Avoid copies on bytes-like objects.. Zero-copy buffer access. That is exactly the concept behind how is memoryview best characterized in this context. The remaining choices fail because they don’t satisfy the full definition.
Q89. Which option best describes functools.lru_cache?
Select an answer to check.
Answer: Memoize function results.
For this question, Memoize function results. is correct. Speeds repeated calls. That is exactly the concept behind which option best describes functools.lru_cache in this context. The remaining choices fail because they don’t satisfy the full definition.
Q90. What is the primary purpose of functools.lru_cache?
Select an answer to check.
Answer: Memoize function results.
Memoize function results. is the correct answer here. Speeds repeated calls. That is exactly the concept behind what is the primary purpose of functools.lru_cache in this context. The remaining choices fail because they don’t satisfy the full definition.
Q91. Which statement about functools.lru_cache is most accurate?
Select an answer to check.
Answer: Memoize function results.
Here, Memoize function results. is the right choice. Speeds repeated calls. It fits the requirement in the prompt about which statement about functools.lru_cache is most accurate. The remaining choices fail because they don’t satisfy the full definition.
Q92. How is functools.lru_cache best characterized?
Select an answer to check.
Answer: Memoize function results.
In this case, Memoize function results. is correct. Speeds repeated calls. It fits the requirement in the prompt about how is functools.lru_cache best characterized. The remaining choices fail because they don’t satisfy the full definition.
Q93. Which option best describes profiling guided optimization?
Select an answer to check.
Answer: Optimize the actual hot paths.
The best option here is Optimize the actual hot paths.. Measure first, then optimize. It fits the requirement in the prompt about which option best describes profiling guided optimization. The remaining choices fail because they don’t satisfy the full definition.
Q94. What is the primary purpose of profiling guided optimization?
Select an answer to check.
Answer: Optimize the actual hot paths.
For this question, Optimize the actual hot paths. is correct. Measure first, then optimize. It fits the requirement in the prompt about what is the primary purpose of profiling guided. The remaining choices fail because they don’t satisfy the full definition.
Q95. Which statement about profiling guided optimization is most accurate?
Select an answer to check.
Answer: Optimize the actual hot paths.
Optimize the actual hot paths. is the correct answer here. Measure first, then optimize. It fits the requirement in the prompt about which statement about profiling guided optimization is most. The remaining choices fail because they don’t satisfy the full definition.
Q96. How is profiling guided optimization best characterized?
Select an answer to check.
Answer: Optimize the actual hot paths.
Here, Optimize the actual hot paths. is the right choice. Measure first, then optimize. This is the most accurate statement for how is profiling guided optimization best characterized. The remaining choices fail because they don’t satisfy the full definition.
Q97. Which option best describes data layout?
Select an answer to check.
Answer: Prefer arrays of numbers over lists of objects.
In this case, Prefer arrays of numbers over lists of objects. is correct. Cache-friendly and vectorizable. This is the most accurate statement for which option best describes data layout. The remaining choices fail because they don’t satisfy the full definition.
Q98. What is the primary purpose of data layout?
Select an answer to check.
Answer: Prefer arrays of numbers over lists of objects.
The best option here is Prefer arrays of numbers over lists of objects.. Cache-friendly and vectorizable. This is the most accurate statement for what is the primary purpose of data layout. The remaining choices fail because they don’t satisfy the full definition.
Q99. Which statement about data layout is most accurate?
Select an answer to check.
Answer: Prefer arrays of numbers over lists of objects.
For this question, Prefer arrays of numbers over lists of objects. is correct. Cache-friendly and vectorizable. This is the most accurate statement for which statement about data layout is most accurate. The remaining choices fail because they don’t satisfy the full definition.
Q100. How is data layout best characterized?
Select an answer to check.
Answer: Prefer arrays of numbers over lists of objects.
Prefer arrays of numbers over lists of objects. is the correct answer here. Cache-friendly and vectorizable. This is the most accurate statement for how is data layout best characterized. The remaining choices fail because they don’t satisfy the full definition.