Free Python Institute PCPP-32-101 Practice Exam with Questions & Answers

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.

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.

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

In the JSON processing context, the term serialization: A. names a process in which Python data is turned into a JSON string.

Serialization refers to the process of converting a data object, such as a Python object, into a format that can be easily transferred over a network or stored in a file. In the case of JSON, serialization refers to converting Python data into a string representation using the JSON format. This string can be sent over a network or stored as a file, and later deserialized back into the original Python data object.

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.

B. 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.

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

The unbind_all() method in Tkinter is used to remove all event bindings from a widget. It is a method of the widget object and can be called on any widget in the Tkinter application. Therefore, option A is the correct answer.

Option B is incorrect because the method can be called on any widget, not just the main window widget.

Option C is correct as unbind_all() does not take any parameters.

Option D is incorrect because the method only removes event bindings and does not cause the widgets to disappear.

So, the correct answers are A and C.

References:

• Tkinter documentation: https://docs.python.org/3/library/tkinter.html#event-bindings
• Tkinter tutorial: https://www.python-course.eu/tkinter_events_binds.php

The dump() method in the xml.etree.ElementTree module allows you to output a debug representation of an XML tree to a file or standard output. This method is useful for analyzing the structure of the tree and tracking down errors.

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 browser1.

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 not2.

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 not3.

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 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.

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.

 The true statement about the __name__ attribute is D. name is a special attribute, which is inherent for classes, and it contains the name of a class. The __name__ attribute is a special attribute of classes that contains the name of the class as a string.

The __name__ attribute is a special attribute in Python that is available for all classes, and it contains the name of the class as a string. The __name__ attribute can be accessed from both the class and its instances using the dot notation.