Explanation
The correct answer is B. The getNumberofCrosswords() method should be decorated with @classmethod. In the given code snippet, the getNumberofCrosswords method is intended to be a class method that returns the value of the numberofcrosswords class variable. However, the method is not decorated with the @classmethod decorator and does not take a cls parameter representing the class itself. To make getNumberofCrosswords a proper class method, it should be decorated with @classmethod and take a cls parameter as its first argument.
The getNumberofCrosswords() method should be decorated with @classmethod.
This is because the getNumberofCrosswords() method is intended to access the class-level variable numberofcrosswords, but it is defined as an instance method, which requires an instance of the class to be created before it can be called. To make it work as a class-level method, you can define it as a class method by adding the @classmethod decorator to the function.
Here’s an example of how to define getNumberofCrosswords() as a class method:
classCrossword:
numberofcrosswords =0
def __init__(self, author, title):
self.author = author
self.title = title
Crossword.numberofcrosswords +=1
@classmethod
defgetNumberofCrosswords(cls):
returncls.numberofcrosswords
In this example, getNumberofCrosswords() is defined as a class method using the @classmethod decorator, and the cls parameter is used to access the class-level variable numberofcrosswords.

Explanation
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.
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.
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.
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.
References:
https://docs.python.org/3/library/requests.html : https://en.wikipedia.org/wiki/Localhost :
https://en.wikipedia.org/wiki/Port_(computer_networking) :
https://en.wikipedia.org/wiki/Fully_qualified_domain_name

Explanation
Composition is an object-oriented design concept that models a has-a relationship. In composition, a class known as composite contains an object of another class known as component. In other words, a composite class has a component of another class1.
Composition allows a class to be projected as a container of different classes.
Composition is a concept in Python that allows for building complex objects out of simpler objects, by aggregating one or more objects of another class as attributes. The objects that are aggregated are generally considered to be parts of the whole object, and the containing object is often viewed as a container for the smaller objects.
In composition, objects are combined in a way that allows for greater flexibility and modifiability than what inheritance can offer. With composition, it is possible to create new objects by combining existing objects, by using a container object to host other objects. By contrast, with inheritance, new objects extend the behavior of their parent classes, and are limited by that inheritance hierarchy.
References:
* Official Python documentation on
Composition: https://docs.python.org/3/tutorial/classes.html#composition
* GeeksforGeeks article on Composition vs
Inheritance: https://www.geeksforgeeks.org/composition-vs-inheritance-python/
* Real Python article on Composition and
Inheritance: https://realpython.com/inheritance-composition-python/

Explanation
ElementTree is a Python built-in module that provides a simple and efficient API for parsing and creating XML data. It allows you to access and manipulate XML data in a very straightforward way, making it easy to write XML processing applications.

Explanation
answer A. Deserialization is the process of converting data that has been serialized or encoded in a specific format, back into its original form as an object or a data structure in memory. In Python, this typically involves creating Python objects based on sequences of bytes that have been serialized using a protocol such as JSON, Pickle, or YAML.
For example, if you have a Python object my_obj and you want to serialize it to a JSON string, you might do something like this:
importjson
serialized_obj = json.dumps(my_obj)
To deserialize the JSON string back into a Python object, you would use the json.loads() method:
deserialized_obj = json.loads(serialized_obj)
This would convert the JSON string back into its original Python object form.

Explanation
In the given code snippet, the repeat function is a decorator that takes an argument num_times specifying the number of times the decorated function should be called. The repeat function returns an inner function wrapper_repeat that takes a function func as an argument and returns another inner function wrapper that calls func num_times times.
The provided code snippet represents an example of a decorator that accepts its own arguments.
The @decorator_function syntax is used to apply the decorator_function to the some_function function.
The decorator_function takes an argument arg1 and defines an inner function wrapper_function that takes the original function func as its argument. The wrapper_function then returns the result of calling func, along with the arg1 argument passed to the decorator_function.
Here is an example of how to use this decorator with some_function:
@decorator_function(“argument 1”)
defsome_function():
return”Hello world”
When some_function is called, it will first be passed as an argument to the decorator_function.
The decorator_function then adds the string “argument 1” to the result of calling some_function() and returns the resulting string. In this case, the final output would be “Hello world argument 1”.

Explanation
The two true statements related to PEP 8 programming recommendations for code writing are Option B and Option D.
Option B is true because PEP 8 recommends making object type comparisons using the isinstance() method instead of comparing types directly 1.
Option D is true because PEP 8 recommends not writing string literals that rely on significant trailing whitespaces as they may be visually indistinguishable, and certain editors may trim them 1.

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

Explanation
A static method is a method that belongs to a class rather than an instance of the class. It is defined using the @staticmethod decorator and does not take a self or cls parameter. Static methods are often used to define utility functions that do not depend on the state of an instance or the class itself.

Explanation
The correct answer is D. The code is responsible for the support of the inequality operator i.e. i != j. In the given code snippet, the __ne__ method is a special method that overrides the behavior of the inequality operator != for instances of the MyClass class. When the inequality operator is used to compare two instances of MyClass, the __ne__ method is called to determine whether the two instances are unequal.

Explanation
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.

Explanation
Option B is correct because it sets the font option of the button to a tuple containing the font family (‘Arial’), size (12), and style (‘italic’).
Option C is correct because it sets the font option of the button to a string containing the font family (‘Arial’), size (12), and style (‘italic’) separated by spaces.

Explanation
The correct answer is C. Excalibur is the value passed to an instance variable. In the given code snippet, self.name is an instance variable of the Sword class. When an instance of the Sword class is created with varl = Sword(‘Excalibur’), the value ‘Excalibur’ is passed as an argument to the __init__ method and assigned to the name instance variable of the varl object.
The code defines a class called Sword with an __init__ method that takes one parameter name. When a new instance of the Sword class is created with varl = Sword(‘Excalibur’), the value of the ‘Excalibur’ string is passed as an argument to the __init__ method, and assigned to the self.name instance variable of the varl object.

Explanation
w.resizable()
The resizable() method takes two Boolean arguments, width and height, that specify whether the main window can be resized in the corresponding directions. Passing False to both arguments makes the main window non-resizable, whereas passing True to both arguments (or omitting them) makes the window resizable.
Here is an example that sets the dimensions of the main window to 500×400 pixels and makes it non-resizable:
importtkinter as tk
root = tk.Tk()
root.geometry(“500×400”)
root.resizable(False, False)
root.mainloop()
References:
* Tkinter documentation: https://docs.python.org/3/library/tk.html
* Tkinter tutorial: https://www.python-course.eu/python_tkinter.php
The resizable () method of a tkinter window object allows you to specify whether the window can be resized by the user in the horizontal and vertical directions. You can pass two boolean arguments to this method, such as w.resizable (False, False), to prevent both dimensions from being changed. Alternatively, you can pass 0 or
1 as arguments, such as w.resizable (0, 0), to achieve the same effect1.
References:
1: https://stackoverflow.com/questions/36575890/how-to-set-a-tkinter-window-to-a-constant-size Other methods that can be used to control the window size are:
* w.geometry () : This method allows you to set the initial size and position of the window by passing a string argument in the format “widthxheight+x+y”, such as w.geometry (“500×500+100+100”)12.
* w.minsize () and w.maxsize (): These methods allow you to set the minimum and maximum size of the window in pixels, such as w.minsize (500, 500) and w.maxsize (1000, 1000)12.
* w.pack_propagate () and w.grid_propagate (): These methods allow you to enable or disable the propagation of the size of the widgets inside the window to the window itself. By default, these methods are set to True, which means that the window will adjust its size according to the widgets it contains.
You can set these methods to False or 0 to prevent this behavior, such as w.pack_propagate (0) or w.grid_propagate (0).
* w.place (): This method allows you to place the window at a specific position and size relative to its parent window or screen. You can use keyword arguments such as x, y, width, height, relx, rely, relwidth, and relheight to specify the coordinates and dimensions of the window in absolute or relative terms, such as w.place (x=0, y=0, relwidth=1, relheight=1).
References:
2: https://stackoverflow.com/questions/25690423/set-window-dimensions-in-tkinter-python-3 :
https://stackoverflow.com/questions/36575890/how-to-set-a-tkinter-window-to-a-constant-size/36576068#36576
https://www.skotechlearn.com/2020/06/tkinter-window-position-size-center-screen-in-python.html

Explanation
Option A is true because PEP 8 recommends that function and variable names should be lowercase, with words separated by underscores .
Option D is true because PEP 8 recommends that constants should be written in all capital letters with words separated by underscores .
PEP 8 is the official style guide for Python code. It provides guidelines for how to write readable code that follows consistent naming conventions. The aim of PEP 8 is to improve the readability of Python code and make it easier to understand and maintain.
According to PEP 8, variable and function names should be written in all lower-case letters with words separated by underscores, as stated in A. Constants, which are variables whose value is expected to remain constant throughout the code, should be written in all upper-case letters with words separated by underscores, as stated in D.
References:
* PEP 8 — Style Guide for Python Code: https://www.python.org/dev/peps/pep-0008/
* Python Documentation: https://docs.python.org/3/tutorial/classes.html#classmethods-and-staticmethods

Explanation
According to PEP 8, Python’s official style guide, line breaks before binary operators produce more readable code, especially in code blocks with long expressions. This is stated in several sources (1,2,6,8) and is a widely accepted convention.
References:
* https://www.python.org/dev/peps/pep-0008/#should-a-line-break-before-or-after-a-binary-operator
* https://stackoverflow.com/questions/30614124/are-long-lines-broken-up-before-or-after-binary-operators-
* https://www.quora.com/What-is-PEP-8-Python
* https://www.techbeamers.com/python-tutorial-pep-8/
* https://www.section.io/engineering-education/python-coding-conventions-guidelines-for-python-programm
* https://towardsdatascience.com/a-step-in-pep8-style-guide-improving-the-readability-of-the-code-8114fd4
* https://www.codementor.io/@rishikeshdhokare/python-coding-style-best-practices-that-every-python-prog
* https://www.dataschool.io/python-pep8-tips-and-tricks/

Explanation
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 browser1.
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 not2.
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 not3.
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 over4.
References:
1: https://www.techtarget.com/searchnetworking/definition/client-server 2:
https://www.javatpoint.com/connection-oriented-vs-connectionless-service 3:
https://en.wikipedia.org/wiki/Walkie-talkie 4: https://en.wikipedia.org/wiki/Telephone_call A is true because in the context of TCP/IP networks, the communication side that initiates a connection is called the client, and the side that answers the client is called the server. This is the basis for establishing a connection-oriented communication.
D is true because a phone call is an example of a connection-oriented communication. Like TCP/IP, a phone call establishes a connection between two devices (in this case, two phones) before communication can occur.
A is true because in the context of TCP/IP networks, the communication side that initiates a connection is called the client, and the side that answers the client is called the server. This is the basis for establishing a connection-oriented communication.
D is true because a phone call is an example of a connection-oriented communication. Like TCP/IP, a phone call establishes a connection between two devices (in this case, two phones) before communication can occur.
B is false because connectionless communications are usually built on top of UDP, not TCP. UDP is a connectionless protocol that does not establish a connection before sending data.
C is false because using walkie-talkies is an example of a connectionless communication. Walkie-talkies do not establish a connection before communication begins, and messages are simply broadcasted to all devices within range.
Here is a sample code in Python using the socket module to create a TCP server and client to demonstrate the connection-oriented communication:
Server-side code:
importsocket
HOST =’127.0.0.1′
PORT =8080
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.bind((HOST, PORT))
s.listen()
conn, addr = s.accept()
with conn:
print(‘Connected by’, addr)
whileTrue:
data = conn.recv(1024)
ifnotdata:
break
conn.sendall(data)
Client-side code:
importsocket
HOST =’127.0.0.1′
PORT =8080
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.connect((HOST, PORT))
s.sendall(b’Hello, world’)
data = s.recv(1024)
print(‘Received’,repr(data))
The server listens for incoming connections on port 8080, and when a connection is established, it prints the address of the client that has connected. The server then continuously receives data from the client and sends it back to the client until the connection is closed.
The client establishes a connection with the server and sends the message “Hello, world” encoded as bytes. It then waits for a response from the server and prints the data it receives.