PCAP Multiple Select — 20 Questions

Question 1

Which THREE statements about inheritance in Python are correct?

Accepted Answer

A child class inherits all attributes and methods from its parent class.. In Python, a child class inherits all non-private attributes and methods from its parent class by default. This includes both data attributes and methods, allowing the child to reuse and extend the parent's behavior without redefinition. Private attributes (with double underscore prefix) are name-mangled to _Classname__attribute, but they are still inherited in the sense that they exist in the child's namespace under the mangled name, though direct access by the original name is restricted.

Answer

Private attributes (with __) are inherited unchanged.

Answer

Python supports method overloading based on parameters.

Question 2

Which THREE of the following statements about Python's module search path are true?

Accepted Answer

The PYTHONPATH environment variable can be used to add custom directories to sys.path.. The PYTHONPATH environment variable is a standard mechanism for extending Python's module search path. When Python starts, it reads the PYTHONPATH variable and prepends its contents to sys.path, allowing users to specify additional directories where Python should look for modules before falling back to the default search order.

Answer

The site-packages directory is searched before the PYTHONPATH directories.

Answer

The current working directory is always the last entry in sys.path.

Question 3

Which TWO of the following statements about Python's `sys.path` are true?

Accepted Answer

Module search stops at the first matching directory in `sys.path`.. Python's import mechanism iterates through `sys.path` in order and stops at the first directory containing the requested module. Option E is correct: the directory containing the script (or the current directory when running interactively) is inserted at the beginning of `sys.path` at startup. Options A, C, and D are false: the current working directory is not always first (the script's directory takes precedence), `sys.path` is initialized from the `PYTHONPATH` environment variable *in addition to* default paths, and `sys.path` is a list, not a tuple. Therefore, only two statements are true.

Answer

The current working directory is always the first element in `sys.path`.

Answer

`sys.path` is initialized from the PYTHONPATH environment variable.

Answer

`sys.path` is a tuple of strings.

Question 4

Which three statements about the Method Resolution Order (MRO) in Python are true? (Choose three.)

Accepted Answer

The MRO can be viewed using the __mro__ attribute.. Every Python class has an `__mro__` attribute that returns a tuple of classes in the order they are searched for methods and attributes. This attribute is automatically generated by the C3 linearization algorithm and provides a clear, inspectable view of the resolution order.

Answer

The MRO is only used for methods, not attributes.

Answer

The MRO can be changed by modifying the class hierarchy at runtime.

Question 5

Which THREE of the following are true about the `__init__` method in Python?

Accepted Answer

It can be called manually.. The __init__ method is a special method in Python classes used for initializing newly created objects. It can be called manually (e.g., obj.__init__()), it accepts arguments that are passed during instance creation, and it is automatically invoked when an instance is created via the class constructor. It does not require a return value (it returns None), and it is inherited by subclasses unless explicitly overridden.

Answer

It must return a value.

Answer

It is not inherited.

Question 6

Which TWO of the following statements about class attributes in Python are true?

Accepted Answer

Class attributes are shared by all instances.. Class attributes are defined directly in the class body and are shared across all instances of that class. When you access a class attribute via any instance, Python looks up the attribute in the class's __dict__ if it is not shadowed by an instance attribute, ensuring all instances see the same value unless explicitly overridden.

Answer

Class attributes are always immutable.

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Class attributes are defined inside methods.

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Modifying a class attribute via an instance modifies it for all instances.

Question 7

Which TWO statements about Python's name mangling are correct?

Accepted Answer

The mangled name format is _ClassName__attribute.. Python's name mangling transforms an attribute name like `__attribute` defined in a class `MyClass` into `_MyClass__attribute`. This mechanism is specifically designed to avoid name clashes in subclasses, not to enforce privacy. The transformation is done by the compiler at definition time, not at runtime.

Answer

Name mangling applies to all method names that start with a single underscore.

Answer

Name mangling prevents external code from accessing the attribute entirely.

Answer

Name mangling occurs at runtime.

Question 8

Given s = 'a1b2c3', which TWO of the following expressions return the string '123'?

Accepted Answer

s[1::2]. Slicing with `s[1::2]` starts at index 1 (the character '1'), goes to the end of the string, and takes every second character, resulting in '1', '2', '3' concatenated as '123'. Option C is also correct because `s[1:6:2]` starts at index 1, stops before index 6 (the string length is 6, so index 6 is just past the last character), and steps by 2, yielding the same sequence of characters.

Answer

s[0:5:2]

Answer

s[0::2]

Answer

s[2:5:1]

Question 9

Which THREE of the following are true about method overriding in Python?

Accepted Answer

The subclass method must have the same name.. Method overriding in Python requires the subclass method to have the same name as the parent class method. This is the fundamental rule of overriding — without the same name, the method is not overriding but rather defining a new method. The subclass method replaces the inherited method when called on an instance of the subclass.

Answer

The `@override` decorator is required.

Answer

The subclass method can have a different number of parameters.

Question 10

Which THREE of the following escape sequences are valid in a Python string and represent a single character? (Select exactly three.)

Accepted Answer

\'. The backslash followed by a single quote (\') is a valid escape sequence in Python that represents a literal single quote character, allowing it to appear inside a single-quoted string without terminating the string. This sequence is interpreted as a single character by the Python parser.

Answer

\x

Answer

\q

Question 11

Which THREE of the following are valid ways to create a string in Python?

Accepted Answer

'world'. All five options are valid ways to create a string in Python. 'world' (A) is a single-quoted string literal, str(['h','i']) (B) uses the str() constructor to convert a list into its string representation ''['h', 'i']'', '''multi-line''' (C) is a triple-quoted string literal, str(None) (D) converts the None object into the string 'None', and 'hello' (E) is a double-quoted string literal. The str() function returns a string for any argument, making B and D just as valid as the literals A, C, and E.

Question 12

Which TWO of the following can be used to remove leading whitespace (spaces, tabs, newlines) from a string? (Choose exactly 2 correct answers.)

Accepted Answer

lstrip(). The `lstrip()` method removes all leading whitespace characters (spaces, tabs, newlines) from the left side of a string. `strip()` removes leading and trailing whitespace, so it also satisfies the requirement of removing leading whitespace. Both are built-in string methods in Python.

Answer

rstrip()

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trim()

Answer

clean()

Question 13

Which THREE of the following are immutable types in Python?

Accepted Answer

str. (str) is correct because strings in Python are immutable sequences of Unicode code points. Once a string object is created, its contents cannot be changed; any operation that appears to modify a string (e.g., concatenation or slicing) actually creates a new string object in memory.

Answer

bytearray

Answer

list

Question 14

Which TWO of the following are valid ways to import a function 'foo' from a module 'bar' that is located in a package 'mypackage'?

Accepted Answer

from mypackage.bar import foo. The syntax `from mypackage.bar import foo` directly imports the function `foo` from the module `bar` within the package `mypackage`. This is the standard Python import statement for importing a specific attribute from a submodule.

Answer

from mypackage import bar.foo

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from . import bar.foo

Answer

import mypackage.bar.foo

Question 15

Which TWO statements about the 'from package import *' statement are correct?

Accepted Answer

If __all__ is defined in __init__.py, only the names in __all__ are imported.. When `__all__` is defined in a package's `__init__.py`, the `from package import *` statement imports only the names listed in that `__all__` list. This is the explicit mechanism Python provides to control the public API of a package when using the wildcard import syntax.

Answer

It imports the package itself as a module.

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Without __all__, it imports all public names from the package's __init__.py and all submodules.

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It imports all submodules of the package by default.

Question 16

Which THREE factors influence Python's module search path (sys.path)?

Accepted Answer

The site-packages directory where pip installs packages. The site-packages directory is automatically included in sys.path by the site module during Python's initialization. This directory is the default location where pip installs third-party packages, making them importable without manual path manipulation.

Answer

The HOME environment variable

Answer

The current working directory at runtime

Question 17

Which TWO of the following are special methods in Python?

Accepted Answer

`__init__`. `__init__` is a predefined special method in Python used as a constructor to initialize an object's state when an instance of a class is created. It is automatically invoked by the Python runtime upon object instantiation, making it a core part of the object-oriented programming model in Python.

Answer

`__bar__`

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`__main__`

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`__foo__`

Question 18

Which THREE are valid ways to create a multiline string in Python?

Accepted Answer

s = ('Line1
' 'Line2'). Options A, B, and C are all valid ways to create a multiline string in Python. Option A uses implicit string concatenation within parentheses; the `
` escape sequence inserts a newline, resulting in a multiline string. Option B uses triple double quotes to span multiple lines physically, preserving line breaks. Option C uses triple single quotes, which work identically to triple double quotes for multiline strings. Option D uses a backslash for line continuation, which does not insert a newline into the string—it just continues the literal on the next line, so the result is a single-line string without a newline. Option E causes a syntax error because a single-quoted string literal cannot span multiple lines without a continuation character.

Answer

s = "Line1\
Line2"

Answer

s = 'Line1
Line2'

Question 19

Which THREE of the following statements about Python's 'with' statement are true? (Select exactly 3)

Accepted Answer

It can be used with any object that implements __enter__ and __exit__ methods.. The 'with' statement in Python is designed to work with any object that implements the context management protocol, which consists of the __enter__ and __exit__ methods. This allows the 'with' statement to manage resources beyond just files, such as database connections, locks, or network sockets, as long as the object provides these two methods.

Answer

It eliminates the need for try/finally blocks for resource management.

Answer

It can only be used with file objects.

Question 20

Which TWO of the following string methods modify the string in place? (Note: Python strings are immutable.)

Accepted Answer

str.lower(). None of the listed string methods modify the string in place because Python strings are immutable. All string methods return a new string rather than altering the original. Therefore, there are no correct options for this question.

Answer

str.join()

Answer

str.replace()

Answer

str.strip()