Python Institute PCPP-32-101 Exam Questions

1. w.resizable()

Theresizable()method takes two Boolean arguments,widthandheight, that specify whether the main window can be resized in the corresponding directions. PassingFalseto both arguments makes the main window non-resizable, whereas passingTrueto both arguments (or omitting them) makes the window resizable.

Here is an example that sets the dimensions of the main window to 500x400 pixels and makes it non-resizable:

import tkinter as tk

root = tk.Tk()

root.geometry('500x400')

root.resizable(False, False)

root.mainloop()

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.

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 (''500x500+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).

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#36576068 : https://www.skotechlearn.com/2020/06/tkinter-window-position-size-center-screen-in-python.html

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.

This statement is true because ElementTree is a module in the standard library of Python that provides an API for working with XML data. The module supports parsing XML from strings or files, creating XML trees from scratch or modifying existing ones, searching and iterating over XML elements, and writing XML data to strings or files.

The provided code snippet defines a functionf1that accepts variable-length arguments using the*argsand**kwargssyntax. The*argsparameter allows for an arbitrary number of unnamed arguments to be passed to the function as a tuple, while the**kwargsparameter 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:

1. The*argsparameter holds a list of unnamed parameters, while the**kwargsparameter holds a dictionary of named parameters.

Official Python documentation on Function definitions:https://docs.python.org/3/tutorial/controlflow.html#defining-functions

Thearg parameter holds a list of unnamed parameters. In the given code snippet, thef1function takes two arguments:*argand**kwarg. The*argsyntax in the function signature is used to pass a variable number of non-keyword (positional) arguments to the function. Inside the function,argis a tuple containing the positional arguments passed to the function. The**kwargsyntax in the function signature is used to pass a variable number of keyword arguments to the function. Inside the function,kwargis a dictionary containing the keyword arguments passed to the function.

1. 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.

2. 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.

3. 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.

4. 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.

1: https://www.techtarget.com/searchnetworking/definition/client-server2: https://www.javatpoint.com/connection-oriented-vs-connectionless-service3: https://en.wikipedia.org/wiki/Walkie-talkie4: 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 thesocketmodule to create a TCP server and client to demonstrate the connection-oriented communication:

Server-side code:

import socket

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)

while True:

data = conn.recv(1024)

if not data:

break

conn.sendall(data)

Client-side code:

import socket

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.

In Python,typeis the built-in metaclass that serves as the base class for all new-style classes. All new-style classes in Python, including built-in types likeintandstr, are instances of thetypemetaclass and inherit from it.