PCEP Practice Test 19 — 15 Questions

Question 1

How many times will the following loop print 'Hi'?

for i in range(3):
    print('Hi')

Accepted Answer

3. The loop `for i in range(3):` iterates exactly three times because `range(3)` generates the sequence 0, 1, 2. Each iteration executes `print('Hi')`, so 'Hi' is printed three times. Option B is correct.

Answer

2

Answer

0

Answer

4

Question 2

Which operator is used for integer division in Python?

Accepted Answer

//. The // operator in Python performs floor division, which returns the integer quotient after dividing two numbers, discarding any fractional remainder. For example, 7 // 2 yields 3, not 3.5, making it the explicit integer division operator.

Answer

%

Answer

**

Answer

/

Question 3

A junior developer is writing a script to process a list of user IDs: ids = [101, 102, 103, 104]. The goal is to create a new list where each ID is increased by 10, without modifying the original list. The developer writes: new_ids = ids.append(10). However, the output shows None. The developer needs to correctly create the new list. Which code should the developer use to achieve this?

Accepted Answer

new_ids = [id + 10 for id in ids]. It uses a list comprehension to create a new list by adding 10 to each element of the original list `ids`, leaving the original list unchanged. The `append()` method modifies the list in place and returns `None`, which is why the developer got `None`.

Answer

for i in range(len(ids)): ids[i] += 10; new_ids = ids

Answer

new_ids = ids + 10

Answer

new_ids = map(lambda x: x+10, ids)

Question 4

A program prints a greeting: name = input("Enter name: "); print("Hello, " + name + "!"). If user enters "Alice", what is output?

Accepted Answer

Hello, Alice!. The `print` function concatenates the string literals and the variable `name` using the `+` operator exactly as specified. When the user enters "Alice", the expression `"Hello, " + name + "!"` becomes `"Hello, Alice!"` — the space after the comma is part of the first string literal, and the exclamation mark is part of the last string literal, producing the output exactly as shown in option A.

Answer

Hello,Alice !

Answer

Hello,Alice!

Answer

Hello, Alice !

Question 5

A programmer wants to create a list of even numbers from 0 to 10 inclusive. Which list comprehension is correct?

Accepted Answer

[x for x in range(0,11) if x%2==0]. It uses `range(0,11)` to generate numbers from 0 to 10 inclusive, and the condition `if x%2==0` selects only even numbers (where the remainder when divided by 2 is 0). This matches the requirement exactly.

Answer

[x for x in range(0,10) if x%2==0]

Answer

[x for x in range(0,11) if x%2]

Answer

[x for x in range(0,11) if x%2==1]

Question 6

Which code correctly creates a list of squares for numbers 1 to 5 using a list comprehension?

Accepted Answer

squares = [x**2 for x in range(1,6)]. It uses the proper syntax for a list comprehension: `[expression for item in iterable]`. Here, `x**2` computes the square, and `range(1,6)` generates numbers 1 through 5 (since range excludes the stop value). This produces the list `[1, 4, 9, 16, 25]`.

Answer

squares = [x**2 for x in range(5)]

Answer

squares = [x^2 for x in (1,2,3,4,5)]

Answer

squares = [x^2 for x in [1,2,3,4,5]]

Question 7

What is the output of the following code?
```python
print('Hello', 'World', sep='-')
```

Accepted Answer

Hello-World. The `print()` function's `sep` parameter specifies the separator between multiple arguments. By default, `sep` is a space, but here it is explicitly set to `'-'`, so the output joins 'Hello' and 'World' with a hyphen, producing 'Hello-World'. Option D is correct because the hyphen is placed directly between the two strings without any extra spaces.

Answer

HelloWorld

Answer

Hello - World

Answer

Hello World

Question 8

A developer runs the code from the exhibit and gets the error shown. Which of the following is the most likely cause?

Accepted Answer

The variable 'result' was never assigned a value.. The error message indicates that the variable 'result' is referenced before it has been assigned any value. In Python, using a variable that has never been assigned raises a NameError. The code attempts to print 'result', but no assignment to 'result' exists in the provided code, so Python cannot resolve the name.

Answer

There is a typo in the variable name.

Answer

The print function requires an import.

Answer

The variable 'result' is a string, not an integer.

Question 9

Arrange the steps to slice a list in Python.

Accepted Answer

First create the list, then specify the start index, then specify the stop index, then optionally specify the step.. List slicing in Python uses the syntax [start:stop:step] within square brackets on an existing list. The correct order is to first have the list, then define the start index, then the stop index, and finally an optional step. Common mistakes include putting indices out of order or attempting to slice before the list exists.

Answer

First specify the start index, then create the list, then specify the stop index, then optionally specify the step.

Answer

First create the list, then specify the stop index, then specify the start index, then optionally specify the step.

Answer

First create the list, then specify the start index, then specify the step, then specify the stop index.

Question 10

A developer needs to check if a variable x is between 10 and 20 (inclusive). Which expression is correct?

Accepted Answer

10 <= x <= 20. Python supports chained comparison operators, allowing `10 <= x <= 20` to evaluate whether `x` is between 10 and 20 inclusive. This expression is equivalent to `(10 <= x) and (x <= 20)`, which checks both boundaries simultaneously.

Answer

x > 10 and x < 20

Answer

x < 10 and x < 20

Answer

x >= 10 or x <= 20

Question 11

A programmer needs to read a file line by line and process each line. Which of the following is the most memory-efficient and Pythonic approach?

Accepted Answer

with open('file.txt') as f: for line in f: print(line). It uses a `with` statement to ensure the file is properly closed after the block, and iterating directly over the file object reads one line at a time without loading the entire file into memory. This is both memory-efficient and Pythonic, as it leverages the file object's built-in iterator.

Answer

lines = open('file.txt').read().split('
')

Answer

content = open('file.txt').read().splitlines()

Answer

for line in open('file.txt'): print(line)

Question 12

Arrange the steps to install a third-party Python package using pip.

Accepted Answer

1. Ensure pip is installed. 2. Run 'pip install package_name'. 3. Verify the installation by importing the package in Python.. Installing packages with pip involves checking pip, running install, and verifying.

Answer

1. Run 'pip install package_name'. 2. Check if pip is installed. 3. Verify the installation.

Answer

1. Verify the installation by importing the package. 2. Ensure pip is installed. 3. Run 'pip install package_name'.

Answer

1. Download the package manually from a website. 2. Run 'pip install' with the downloaded file. 3. Check pip version.

Question 13

What is the result of the expression: print(2 ** 3 ** 2) ?

Accepted Answer

512. The expression `2 ** 3 ** 2` uses the exponentiation operator `**`, which in Python is right-associative. This means it is evaluated as `2 ** (3 ** 2)`, not `(2 ** 3) ** 2`. First, `3 ** 2` equals 9, then `2 ** 9` equals 512. Therefore, option A is correct.

Answer

256

Answer

64

Answer

128

Question 14

A developer needs to convert a string '25' to an integer and then add 10. Which code correctly performs this?

Accepted Answer

print(int('25') + 10). `int('25')` converts the string '25' to the integer 25, and then `+ 10` performs integer addition, resulting in 35. The `print()` function outputs the result. This follows Python's type conversion rules where explicit conversion is required to combine a string and an integer in arithmetic.

Answer

print('25' + 10)

Answer

print(int('25') + '10')

Answer

print('25' + str(10))

Question 15

A developer wrote: x = 10; y = 5; x += y * 2. What are the values of x and y after execution?

Accepted Answer

x=20, y=5. The expression `x += y * 2` is evaluated as `x = x + (y * 2)`. Given `x = 10` and `y = 5`, `y * 2` equals 10, then `x + 10` equals 20, so `x` becomes 20. The value of `y` remains unchanged at 5 because the assignment operator `+=` only modifies `x`.

Answer

x=15, y=5

Answer

x=30, y=5

Answer

x=20, y=10