A developer has a list 'matrix' containing sublists (rows). The developer assigns 'copy = matrix' and then modifies copy[0][0] = 99. The developer is surprised to find that matrix[0][0] is also 99. What is the root cause?

Assignment creates a reference, not a copy; both variables point to the same list object.

The copy module was not imported, so assignment performs a deep copy.

Lists are immutable, so modifying one modifies all references.

The developer should have used tuple instead of list to avoid this.

GIAC Python Coder

Domain 1Objective 2

Data Structures GPYC Practice Questions (Page 5)

Part of the Python Fundamentals domain, which makes up ~43% of our current practice bank. GIAC (SANS) does not publish an official question count, but from its 120-minute exam (~50–80 total, ~22–34 in this domain), expect 4–7 from this objective — we provide 37 practice questions to prepare you well beyond it. (estimate)

37questions here

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Questions 21–25

21expert · hard
A developer has a list 'matrix' containing sublists (rows). The developer assigns 'copy = matrix' and then modifies copy[0][0] = 99. The developer is surprised to find that matrix[0][0] is also 99. What is the root cause?
Select an answer first
22foundation · easy
What is the result of the following code? ```python matrix = [[1, 2], [3, 4]] print(matrix[1][0]) ```
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23foundation · easy
Which list method removes the first occurrence of a specified value and raises a ValueError if the value is not present?
Select an answer first
24application · medium
A security analyst has a list 'ip_list' that may contain duplicate IP addresses. The analyst needs to determine how many unique IPs are in the list. Which expression gives the count of unique IPs?
Select an answer first
25foundation · easy
Which dictionary method returns a view object that displays a list of all the values in the dictionary?
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Data Structures GPYC Practice Questions (Page 5)

Questions 21–25

A developer has a list 'matrix' containing sublists (rows). The developer assigns 'copy = matrix' and then modifies copy[0][0] = 99. The developer is surprised to find that matrix[0][0] is also 99. What is the root cause?

What is the result of the following code? ```python matrix = [[1, 2], [3, 4]] print(matrix[1][0]) ```

Which list method removes the first occurrence of a specified value and raises a ValueError if the value is not present?

A security analyst has a list 'ip_list' that may contain duplicate IP addresses. The analyst needs to determine how many unique IPs are in the list. Which expression gives the count of unique IPs?

Which dictionary method returns a view object that displays a list of all the values in the dictionary?

Keep studying — Python Fundamentals