PCAP Strings Practice Test 5 — 15 Questions

Question 1

A beginner programmer writes: name = "Alice"; print("Hello " + name). Which string method alternative is more efficient and recommended for Python 3?

Accepted Answer

print(f"Hello {name}"). F-strings (formatted string literals) are the most efficient and readable string formatting method introduced in Python 3.6. They evaluate expressions at runtime and directly interpolate variables into the string, avoiding the overhead of method calls or the older %-formatting, making them both faster and more Pythonic.

Answer

print("Hello {}".format(name))

Answer

print("Hello %s" % name)

Answer

print("Hello " + name) is fine

Question 2

A function is supposed to return True if a string contains only digits, and False otherwise. Which implementation uses a Python string method correctly?

Accepted Answer

return s.isdigit(). `s.isdigit()` returns True if the string is non-empty and all characters are digit characters as defined by Python (including Unicode digits such as superscripts). It differs from `isdecimal()`, which only accepts decimal digits (0-9), and `isnumeric()`, which accepts any numeric character (including fractions, Roman numerals). The expression `s.isalnum() and not s.isalpha()` would incorrectly accept non-digit numeric characters like fractions.

Answer

return s.isdecimal()

Answer

return s.isnumeric()

Answer

return s.isalnum() and not s.isalpha()

Question 3

Given: s = "Python". Which expression raises an IndexError?

Accepted Answer

s[6]. For s = 'Python', valid positive indices are 0..5, so s[6] is out of range and raises IndexError. Valid negative indices are -1..-6, so s[-10] is also out of range and raises IndexError. Thus both B and C are correct.

Answer

s[-1]

Answer

s[5]

Question 4

Which of the following is a valid way to create an empty string in Python?

Accepted Answer

empty = str(). All options A, B, and D are valid ways to create an empty string in Python. The str() constructor with no arguments returns an empty string, and both single-quoted '' and double-quoted "" are empty string literals. Option C is incorrect because it claims only A and B are valid, excluding D which is also valid.

Answer

Both A and B

Question 5

A developer wants to remove all leading and trailing whitespace from a string, but preserve internal spaces. Which line of code accomplishes this?

Accepted Answer

s = s.strip(). `s.strip()` removes all leading and trailing whitespace characters (spaces, tabs, newlines) from the string while preserving internal spaces. This is the exact requirement: eliminate whitespace at the boundaries only, leaving the internal content unchanged.

Answer

s = s.lstrip()

Answer

s = s.strip().lstrip()

Answer

s = s.replace(' ', '')

Question 6

Consider the following code:
result = ' '.join(['a', 'b', 'c'])
print(repr(result))
What is the output?

Accepted Answer

'a b c'. The `join()` method concatenates the list elements with a space separator, producing the string `'a b c'`. The `repr()` function returns a string representation that includes quotes, so the output is `'a b c'` (with single quotes). Option C is correct because it matches the exact output of `print(repr(result))`.

Answer

['a', 'b', 'c']

Answer

"a b c"

Answer

a b c

Question 7

Which string method would you use to check if a string starts with a specified prefix?

Accepted Answer

startswith(). The correct method to check if a string starts with a specified prefix in Python is `str.startswith()`. It returns `True` if the string begins with the given prefix, otherwise `False`. This method is part of the standard string methods in Python and is case-sensitive by default.

Answer

start_with()

Answer

beginswith()

Answer

startwithcase()

Question 8

Which THREE of the following are valid string methods in Python? (Choose three.)

Accepted Answer

.capitalize(). All three options A, B, and E are valid Python string methods. .capitalize() returns a copy of the string with its first character capitalized and the rest lowercased. .lower() returns a copy of the string with all characters converted to lowercase. .swapcase() returns a copy of the string with uppercase characters converted to lowercase and vice versa. Options C and D are incorrect because .uppercase() and .titlecase() are not valid Python string methods; the correct methods are .upper() and .title(). Although the question asks to choose two, note that .swapcase() is also a valid method, making three correct options. In such cases, any two of the three valid methods would be acceptable, but the intended correct answers are A, B, and E.

Answer

.uppercase()

Answer

.titlecase()

Question 9

Which THREE of the following expressions return the string "Python"? (Choose three.)

Accepted Answer

"Python"[:]. Slicing the entire string with '[:]' returns a copy of the full string, which is 'Python'. This is a common idiom for copying a sequence in Python.

Answer

"Python"[::2]

Answer

"Python"[:-1]

Question 10

Which TWO of the following are valid ways to use string formatting in Python? (Choose two.)

Accepted Answer

"Hello {0}".format("World"). The `str.format()` method with positional index `{0}` is a valid way to insert the argument `"World"` into the string, producing `"Hello World"`. This is a core feature of Python's string formatting, introduced in Python 2.6, and is explicitly tested in the PCAP exam.

Answer

"Hello $s" % "World"

Answer

f"Hello {world}"

Answer

"Hello {name}".format("World")

Question 11

A user entered a string '   Hello, World!   '. Which expression returns 'Hello, World!'?

Accepted Answer

s.strip(). The `strip()` method removes all leading and trailing whitespace characters from a string, returning a new string without the surrounding spaces. In this case, `s.strip()` removes the three leading spaces and three trailing spaces from '   Hello, World!   ', resulting in 'Hello, World!'.

Answer

s.split()

Answer

s.rstrip()

Answer

s.lstrip()

Question 12

A developer writes a log message with variables: name = 'Alice' and age = 30. Which of the following uses an f-string correctly?

Accepted Answer

f'Name: {name}, Age: {age}'. It uses the proper f-string syntax: the letter 'f' immediately followed by a string literal (single or double quotes) containing expressions in curly braces. In Python, f-strings (formatted string literals) evaluate expressions inside {} and insert them into the string at runtime, making them concise and readable.

Answer

f(Name: {name}, Age: {age})

Answer

'Name: %s, Age: %d' % (name, age)

Answer

f.'Name: {name}, Age: {age}'