Exam PCEP-30-02 topic 1 question 36 discussion

C. The code is erroneous.

In Python, the order of operations for arithmetic operators follows PEMDAS (Parentheses, Exponents, Multiplication and Division, Addition and Subtraction), similar to standard mathematical precedence. Operator Precedence in Python (from highest to lowest priority) Precedence Operator(s) Description 1 (Highest) () Parentheses (Expressions inside () are evaluated first) 2 ** Exponentiation (Power) 3 +x, -x Unary plus, Unary minus (e.g., +3, -3) 4 *, /, //, % Multiplication, Division, Floor Division, Modulus (evaluated from left to right) 5 +, - Addition, Subtraction (evaluated from left to right)

C. The code is erroneous. Let's analyze the code: python Copy Edit nums = [1,2,3] data = (('Peter',) * (len (nums)) - nums [::-1][0]) print (data) Step-by-step breakdown: nums = [1,2,3] This creates a list: [1, 2, 3]. len(nums) The length of nums is 3. ('Peter',) * 3 This creates a tuple with three elements: python Copy Edit ('Peter', 'Peter', 'Peter') nums[::-1][0] nums[::-1] reverses the list: [3, 2, 1]. nums[::-1][0] gives 3. ('Peter', 'Peter', 'Peter') - 3 Here, we attempt to subtract an integer (3) from a tuple, which is not a valid operation in Python. Why is the code erroneous? Python does not support arithmetic operations like subtraction (-) between a tuple and an integer. This will raise a TypeError. Error message: bash Copy Edit TypeError: unsupported operand type(s) for -: 'tuple' and 'int' Correct Answer: ✅ C. The code is erroneous.

Let's break down the code step by step: nums = [1, 2, 3] This creates a list nums with the elements 1, 2, and 3. nums[::-1] This reverses the list nums. So, nums[::-1] becomes [3, 2, 1]. nums[::-1][0] This accesses the first element of the reversed list, which is 3. len(nums) - nums[::-1][0] The length of nums is 3 (since there are three elements). Subtracting nums[::-1][0] (which is 3), we get: len(nums) - nums[::-1][0] = 3 - 3 = 0 ('Peter',) * 0 This creates a tuple ('Peter',) and multiplies it by 0. In Python, multiplying a tuple by 0 results in an empty tuple: ('Peter',) * 0 = () print(data) Finally, this prints the value of data, which is an empty tuple. Expected Output: ()

E is the correct answer. Breakdown of data = ('Peter',) * (len(nums) - nums[::-1][0]) len(nums) = 3 nums[::-1] reverses the list so nums would become [3,2,1] nums[0] would then return 3 as the first element When multiplying a tuple, you create that many versions of the current entry. 3-3 becomes 0 and multiplying anything by 0 becomes 0 so there would be 0 entries in the tuple returning ()

e is the correct answer