PCEP Practice Test 1 — 10 Questions

Question 1

According to PEP 8, which of the following is the recommended way to name a constant representing the maximum number of retries?

Accepted Answer

MAX_RETRIES. PEP 8 (Python Enhancement Proposal 8) recommends that constants be named using uppercase letters with underscores separating words, i.e., `MAX_RETRIES`. This convention distinguishes constants from regular variables, which use lowercase with underscores, and helps improve code readability and maintainability.

Answer

max_retries

Answer

1st_retry_limit

Answer

maxRetries

Question 2

A developer writes a function that takes a tuple as an argument and tries to modify an element inside the tuple. What happens?

Accepted Answer

The code raises a TypeError.. Tuples in Python are immutable, meaning their elements cannot be changed after creation. Attempting to modify an element (e.g., `my_tuple[0] = 5`) raises a `TypeError` because the tuple object does not support item assignment. This is a fundamental property of the tuple data type.

Answer

The tuple is converted to a list automatically.

Answer

The first element is modified successfully.

Answer

The code raises a ValueError.

Question 3

The exhibit shows a JSON configuration. Which Python data structure is best suited to represent this configuration?

Accepted Answer

Dictionary. JSON objects map directly to Python dictionaries. Option B (Tuple) is wrong because tuples are immutable and lack key-value mapping. Option C (String) is wrong because a string would lose all structure, making access by key impossible. Option D (List) is wrong because lists are ordered sequences accessed by index, not by key-value pairs.

Answer

Tuple

Answer

String

Answer

List

Question 4

What is the output of the code in the exhibit?

Accepted Answer

3. The code performs integer division using the // operator, which in Python returns the floor of the division result for positive numbers. Since 10 // 3 equals 3 (the integer part of 10/3), the output is 3. Option A is correct because integer division discards the fractional part.

Answer

4

Answer

3.0

Answer

3.3333333333333335

Question 5

A system administrator is writing a Python script to monitor server uptime. The script reads a log file line by line, parses timestamps, and stores them in a list. It then loops through the list to detect gaps longer than 5 minutes that indicate a crash. However, the script keeps missing crashes. The current loop is a for loop that iterates over the list using indices. The administrator suspects the loop logic. The loop uses 'for i in range(len(timestamps)-1): if timestamps[i+1] - timestamps[i] > 300: print("Crash detected")'. Timestamps are integers representing seconds since epoch. What is the most likely cause of missed crashes and the best fix?

Accepted Answer

The timestamps list may not be sorted. The loop assumes timestamps are in chronological order, but if the list is unsorted, adjacent elements may not represent consecutive events, causing the time difference to be negative or misleading, and thus missing actual gaps. Sorting the list before the loop ensures that timestamps[i+1] - timestamps[i] correctly reflects the time between consecutive log entries.

Answer

The loop should use range(len(timestamps)) instead of -1

Answer

The difference should be computed as timestamps[i] - timestamps[i+1]

Answer

The comparison should be > 300, but use > 300.0

Question 6

What does 'print(2 ** 3)' output?

Accepted Answer

8. The ** operator in Python performs exponentiation, raising the left operand (2) to the power of the right operand (3), which equals 8. The print() function then outputs this integer result to the console.

Answer

9

Answer

23

Answer

6

Question 7

Given the code: x = 10; y = 3.0; z = x / y; print(type(z)). What is the output?

Accepted Answer

. In Python, when you divide an integer by a float using the / operator, the result is always a float. Here, x is an integer (10) and y is a float (3.0), so z = 10 / 3.0 evaluates to 3.3333333333333335, which is of type float. The print(type(z)) outputs , making option B correct.

Answer

Answer

Answer

Question 8

Given the code: my_list = [1, 2, 3, 4, 5]. What is the output of print(my_list[-3:-1])?

Accepted Answer

[3, 4]. Python list slicing with negative indices counts from the end of the list. my_list[-3:-1] starts at index -3 (value 3) and goes up to but does not include index -1 (value 5), so it returns [3, 4].

Answer

[4, 5]

Answer

[2, 3]

Answer

[3, 4, 5]

Question 9

A Python script calculates the area of a circle: radius = 5; area = 3.14 * radius ** 2; print(area). What is printed?

Accepted Answer

78.5. 78.5 because the expression `3.14 * radius ** 2` is evaluated according to Python's operator precedence: exponentiation (`**`) has higher precedence than multiplication (`*`), so `radius ** 2` computes 5 squared (25), then multiplied by 3.14 gives 78.5. The `print(area)` function outputs this value.

Answer

157.0

Answer

25.0

Answer

31.4

Question 10

Which loop is more efficient for iterating over a large list when you only need the values, not indices?

Accepted Answer

for value in mylist:. Iterating directly over the list with `for value in mylist:` avoids the overhead of indexing or enumeration. This is the most efficient approach in Python for accessing only the values, as it uses the list's internal iterator, which is implemented in C and involves no function calls or index lookups per iteration.

Answer

for i in range(len(mylist)): value = mylist[i]

Answer

for i, value in enumerate(mylist):

Answer

for value in mylist[::-1]: