PCPP-32-101 Sample Questions Answers

Option B is true because the  unbind()  method is invoked from within a widget’s object  1 .

Option D is true because the  unbind()  method needs the event name as an argument  1 .

The  unbind()  method in Tkinter is used to remove a binding between an event and a function. It can be invoked from within a widget's object when a binding is no longer needed. The method requires the event name as an argument to remove the binding for that specific event. For example:

button = tk.Button(root, text="Click me")

button.bind(" < Button-1 > ", callback_function) # bind left mouse click event to callback_function

button.unbind(" < Button-1 > ") # remove the binding for the left mouse click event

The issue is method resolution order, commonly called MRO. In Python multiple inheritance, the interpreter must build a consistent linear inheritance path for the class. Here, B already inherits from A, meaning B must appear before A in the resolution order. However, class C(A, B) asks Python to resolve A before B. These two requirements conflict, so Python cannot create a valid MRO for class C. This results in a TypeError related to inconsistent method resolution order. The absence of an __init__() method is not a problem because Python supplies a default initializer. Also, C can inherit run() if the inheritance order is valid.

The snippet raises a NameError because the variable height is referenced inside the constructor but is never defined. The __init__() method accepts only weight and sex as parameters, apart from self. When kitty = Cat(1, 'male') is executed, Python enters the constructor and evaluates self.height = height. Since there is no local variable, parameter, global variable, or built-in name called height, Python raises a NameError before the object is fully initialized. Because object construction fails, kitty.say() is never reached. The code does not print meows, and it does not raise ValueError, because the problem is not an invalid value but an undefined name.

The true statement related to PEP 257 is  Option B . According to PEP 257, string literals occurring elsewhere in Python code may also act as documentation. They are not recognized by the Python bytecode compiler and are not accessible as runtime object attributes (i.e. not assigned to  doc ), but two types of extra docstrings may be extracted by software tools: String literals occurring immediately after a simple assignment at the top level of a module, class, or  init  method are called “attribute docstrings”.  String literals occurring immediately after another docstring are called “additional docstrings” 1 .

The provided code snippet defines a function  f1  that accepts variable-length arguments using the  *args  and  **kwargs  syntax. The  *args  parameter allows for an arbitrary number of unnamed arguments to be passed to the function as a tuple, while the  **kwargs  parameter allows for an arbitrary number of named arguments to be passed to the function as a dictionary.

Therefore, the correct statement that best describes the code is:

B. The  *args  parameter holds a list of unnamed parameters, while the  **kwargs  parameter holds a dictionary of named parameters.

The correct answer is C. The code creates an XML root element named data and then adds two child elements named car. Each car element receives a brand attribute, one with the value Audi and the other with the value Volkswagen. The statement tree.write('cars.xml', 'UTF-8', True) writes the XML document using UTF-8 encoding and explicitly enables the XML declaration through the third argument. Because the XML declaration is enabled, the output begins with < ?xml version='1.0' encoding='UTF-8'? > . The generated XML body then contains the data element with two self-closing car child elements. Options without the encoding declaration are therefore incomplete.

The correct answer is D because var1 is a class variable defined directly inside the Sword class body. Class variables belong to the class object itself and can be accessed or updated by qualifying them with the class name, such as Sword.var1 = 'blade'. The snippet does not raise an AttributeError or ValueError; creating s1 = Sword() correctly calls __init__() and assigns the instance attribute self.name. Option C is not correct in this context because cls is only automatically available inside a class method when declared as the first parameter. Outside such a method, cls is just an undefined name unless explicitly assigned.

A. It addresses a service deployed at localhost (the host where the code is run).

This statement is true because localhost is a special hostname that refers to the local machine or the current host where the code is run. It is equivalent to using the IP address 127.0.0.1, which is the loopback address of the network interface. By using localhost as the hostname, the invocation addresses a service that is deployed on the same machine as the client.

D. It addresses a service listening at port 3000.

This statement is true because port 3000 is the part of the URL that follows the colon after the hostname. It specifies the port number where the service is listening for incoming requests. A port number is a 16-bit integer that identifies a specific process or application on a host. By using port 3000, the invocation addresses a service that is listening at that port.

B. It addresses a service whose timeout is set to 3000 ms.

This statement is false because timeout is not a part of the URL, but a parameter that can be passed to the requests.get () function in Python. Timeout specifies how long to wait for the server to send data before giving up. It is measured in seconds, not milliseconds. By using timeout=3, the invocation sets the timeout to 3 seconds, not 3000 ms.

C. It addresses a service located at the following address local.host.com.

This statement is false because local.host.com is not the same as localhost. Local.host.com is a fully qualified domain name (FQDN) that consists of three parts: local, host, and com. It requires DNS resolution to map it to an IP address. Localhost, on the other hand, is a special hostname that does not require DNS resolution and always maps to 127.0.0.1. By using localhost as the hostname, the invocation does not address a service located at local.host.com.

A. In the context of TCP/IP networks, the communication side that initiates a connection is called the client, whereas the side that answers the client is called the server.

This statement is true because TCP/IP networks use a client-server model to establish connection-oriented communications. The client is the device or application that requests a service or resource from another device or application, which is called the server. The server responds to the client’s request and provides the service or resource. For example, when you browse a website using a web browser, the browser acts as a client and sends a request to the web server that hosts the website.  The web server acts as a server and sends back the requested web page to the browser 1 .

B. Connectionless communications are usually built on top of TCP.

This statement is false because TCP (Transmission Control Protocol) is a connection-oriented protocol that requires establishing and terminating a connection before and after sending data. Connectionless communications are usually built on top of UDP (User Datagram Protocol), which is a connectionless protocol that does not require any connection setup or teardown. UDP simply sends data packets to the destination without checking if they are received or not 2 .

C. Using walkie-talkies is an example of a connection-oriented communication.

This statement is false because using walkie-talkies is an example of a connectionless communication. Walkie-talkies do not establish a dedicated channel or connection between the sender and receiver before transmitting data. They simply broadcast data over a shared frequency without ensuring that the receiver is ready or available to receive it.  The sender does not know if the receiver has received the data or not 3 .

D. A phone call is an example of a connection-oriented communication.

This statement is true because a phone call is an example of a connection-oriented communication. A phone call requires setting up a circuit or connection between the caller and callee before exchanging voice data. The caller and callee can hear each other’s voice and know if they are connected or not.  The phone call also requires terminating the connection when the conversation is over 4 .

The  messagebox.askquestion()  method in Python's tkinter library displays a message box with a specified question and two response buttons labeled "Yes" and "No". It returns a string indicating which button was selected - either "yes" or "no".

This function is used to ask questions to the user that have only two options: YES or NO.  It can be used to ask the user if they want to continue or if they want to submit something  1 .

ConfigParser is a built-in library in Python that allows you to read and write configuration files. The read method is used to read the configuration file which can be in any of the supported file formats, such as INI, YAML, and JSON. The read_dict method is used to read the configuration from a Python dictionary. The read_conf and read_str options are not valid methods in the ConfigParser module.

Therefore, the correct options to load a configuration using ConfigParser are A. read and D. read_string.

If you do not define the quoting argument in the writer method provided by the csv module, the default quoting behavior is set to QUOTE_MINIMAL. This means that fields containing special characters such as the delimiter or newline character will be quoted, while fields that do not contain special characters will not be quoted.

If the main window is too small to fit all its widgets,  some widgets may be invisible . So, the correct answer is  Option A .

When a window is not large enough to display all of its content, some widgets may be partially or completely hidden. The window will not automatically expand to fit all of its content, and no exception will be raised. The widgets will not be automatically scaled down to fit the window’s size.

If the main window is too small to fit all its widgets, some of the widgets may not be visible or may be partially visible. This is because the main window has a fixed size, and if there are more widgets than can fit within that size, some of them will be outside the visible area of the window.

To avoid this issue, you can use layout managers such as  grid ,  pack , or  place  to dynamically adjust the size and position of the widgets as the window changes size. This will ensure that all the widgets remain visible and properly arranged regardless of the size of the main window.

The correct answer is B because Python’s pickle module can serialize many built-in data types, including integers, floating-point numbers, complex numbers, strings, bytes, bytearrays, booleans, and None. However, it does not serialize the actual implementation or definition body of functions and classes. Top-level functions and classes may sometimes be pickled by reference using their fully qualified names, but their code definitions are not stored inside the pickle byte stream. This distinction matters: pickle records enough information to locate an object again during unpickling, but it does not preserve source code, nested definitions, lambda functions, or dynamically created definitions in a portable way. Therefore, “function and class definitions” is the option that cannot truly be pickled as definitions.

The correct answers are C and D. In Python’s sqlite3 module, the string ':memory:' is passed to sqlite3.connect() to create an in-memory SQLite database. This establishes a valid database connection, but the database exists only in RAM and normally disappears when the connection is closed. It is useful for testing, temporary storage, fast operations, and examples where no persistent database file is required. Option A is wrong because :memory: does not load an existing file-based database into memory. Option B is also incorrect because it is not a deletion command or database management operation. It is simply a special database name recognized by SQLite to create a temporary in-memory database.

The given code snippet demonstrates the concept of encapsulation in object-oriented programming. Encapsulation refers to the practice of keeping the internal state and behavior of an object hidden from the outside world and providing a public interface for interacting with the object. In the given code snippet, the  __init__  and  get_balance  methods provide a public interface for interacting with instances of the  BankAccount  class, while the  __balance  attribute is kept hidden from the outside world by using a double underscore prefix.

The correct answers are C and D. The json.loads() function is used for JSON deserialization. It accepts a JSON-formatted string, bytes, or bytearray and converts that serialized JSON data into an equivalent Python object. For example, a JSON object becomes a Python dictionary, a JSON array becomes a Python list, JSON strings become Python strings, and JSON numbers become Python numeric values. Option A describes json.dumps(), which takes Python data and serializes it into JSON text. Option B is also incorrect because returning a JSON string is the job of json.dumps(), not json.loads(). Therefore, json.loads() takes JSON text as input and returns a Python entity.