Python Interview Questions
• Python - Loops
 1. What keyword is used for looping? A) while B) for C) loop Answer: for 2. What function can generate a list of numbers? A) for B) list C) range Answer: range 3. Name the 2 keywords used for looping? A) while loop B) for loop C) for while Answer: for while 4. What module is used for generating random values? A) math B) random C) randrange Answer: random 5. What keyword is used to skip back to the beginning of a loop? A) break B) while C) continue Answer: continue 6. What keyword is used to end looping completely? A) end B) break C) continue Answer: break 7. Use range to generate a list from 1 through 5? A) range(1, 5) B) range(5) C) range(1,6) Answer: range(1,6) 8. Select the code needed to generate a random number between 1 through 50 and assign it to rand_num? A) random.randrange(1, 51) B) random.randrange(1, 50) C) random(1, 50) Answer: random.randrange(1, 51) 9. What numbers does the following Range generate: range(5,10)? A) 5,6,7,8,9,10 B) 6,7,8,9,10 C) 5,6,7,8,9 Answer: 5,6,7,8,9 Explanation: Range starts at 5 and goes up to (but not including) 10 10. What numbers does the following range generate range(3)? A) 3 B) 1,2,3 C) 0,1,2,3 D) 0,1,2 Answer: 0,1,2 Explanation: Range will start at 0 and go up to (but not including) 3 11. What is printed out after the following code nums = range(1,5) print(nums)? A) 1,2,3,4 B) range(1,5) Answer: range(1,5) Explanation: Printing range does not print out all the numbers in the range. We have to iterate over the range with a loop to print the numbers. 12. What numbers does the following range generate range(8,0,-2): A) 0,2,4,6 B) 8,6,4,2 C) 8,6,4,2,0 Answer: 8,6,4,2 Explanation: The 3rd argument(step) indicates that range should work backwards from 8, moving 2 numbers at a time. 13. What does the following loop do? i = 1 while i < 5: i + i print(i) A) It prints 1,2,3,4,5 and then exits B) It prints 1,2,4 then exits C) It prints 1 forever Answer: It prints 1 forever Explanation: Don't forget to add the + before the = sign when incrementing! 14. What does the following loop do? # print 1 to 5 i = 0 while i <= 5: i =+ 1 print(i) A) It prints 1 through 5 because it increments i each time B) It prints 0 through 5 because i starts at zero C) It prints 1 forever because there is a typo with the increment which should be += instead of =+. D) It prints zero through four because i starts at zero and goes up until 5. Answer: It prints 1 forever because there is a typo with the increment which should be += instead of =+. 15. What can we do to get out of the infinite loop below? #this code runs forever... x = 0 while x != 11: x += 2 print(x) A) Change the condition to x ! = 10 B) Change the condition to x < 11 C) Add logic that says if x == 10: break D) Press control + C while your program is running to kill it E) All of the above Answer: All of the above 16. For loops are used to loop over: A) Loopy objects B) Numbers C) Iterable objects D) Lines of code Answer: Iterable objects 17. What is the tradeoff when using while loops for looping? A) While loops are more flexible since you explicitly set the start and end conditions, but they require more setup than for loops B) While loops are faster than for loops but require more setup C) While loops can loop infinitely and give you more control, but they cannot be used to iterate over iterable objects Answer: While loops are more flexible since you explicitly set the start and end conditions, but they require more setup than for loops 18. What does the break keyword do? A) Exits the loop at the beginning of the next iteration B) Breaks your code C) Exits the loop at the end of this iteration D) Exits the loop immediately Answer: Exits the loop immediately Explanation: break is the fastest way to get out of a loop -- it won't run any code after the break 19. What does the following code print? for x in range(5): print(x) A) 1 2 3 4 5 B) 1 2 3 4 C) 0 1 2 3 4 Answer: 0 1 2 3 4 Explanation: Python ranges start at zero by default and count up to, but not including, the end number. 