Real Python Institute PCPP-32-101 Exam Questions Study Guide [Q20-Q36]

Explanation
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

Explanation
The socket.gaierror exception is raised when an address-related error caused by the getaddrinfo() and getnameinfo() functions occurs. These functions are used to translate hostnames to IP addresses and vice versa, and the gaierror exception is raised if they fail to perform this translation.

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
The execute method is provided by the Cursor class
This statement is true because the execute method is one of the methods of the Cursor class in the sqlite3 module. The Cursor class represents an object that can execute SQL statements and fetch results from a database connection. The execute method takes an SQL query as an argument and executes it against the database. For example, cur = conn.cursor (); cur.execute (“SELECT * FROM table”) creates and executes a cursor object that selects all rows from a table.
The fetchone method returns None when no rows are available
This statement is true because the fetchone method is another method of the Cursor class in the sqlite3 module.
The fetchone method fetches the next row of a query result set and returns it as a single tuple or None if no more rows are available. For example, row = cur.fetchone () fetches and returns one row from the cursor object or None if there are no more rows.

Explanation
The json.dumps() function is used to convert a Python object into a JSON string 1. It takes Python data as its argument, such as a dictionary or a list, and returns a JSON string.

Explanation
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.

Explanation
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.
References:
* https://www.tkdocs.com/tutorial/widgets.html#managers
* https://www.geeksforgeeks.org/python-tkinter-widgets/
* https://anzeljg.github.io/rin2/book2/2405/docs/tkinter/introduction.html

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
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 answers are A. An attribute owned by every exception object and D. An attribute that holds interesting information that is particularly useful when the programmer wants to store exception details in other objects. A traceback is an attribute of an exception object that contains a stack trace representing the call stack at the point where the exception was raised. The traceback attribute holds information about the sequence of function calls that led to the exception, which can be useful for debugging and error reporting.

Explanation
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.

Explanation
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.

Explanation
The sqlite3 module in python provides an interface compliant to the DB-API 2.0. Thus, it follows a standard performance metric that allows for consistency in database programming with python.
The special name ‘memory’ is used to create a database in RAM using the sqlite3 module. Thus, when you use it as the name of the database file while opening a connection, it creates a temporary database that exists only in memory.

Explanation
In Python, type is 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 like int and str, are instances of the type metaclass and inherit from it.

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
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.