PCPP1 Graphical User Interface Programming — 15 Questions

Question 1

You want to create a button that closes the GUI application when clicked. Which method should you call inside the command callback?

Accepted Answer

root.destroy(). The destroy() method on the root window object terminates the Tkinter application.

Answer

root.close()

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root.exit()

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root.quit()

Question 2

When using the pack geometry manager, you want a widget to fill the available space in the parent container. Which argument for the 'fill' parameter should you use to make it expand in both horizontal and vertical directions?

Accepted Answer

fill=tk.BOTH. fill=tk.BOTH is the correct Tkinter constant to make a widget expand in both horizontal and vertical directions within its allocated space. tk.BOTH is a symbolic constant equal to the string 'both', and it is the documented value for the fill option. Combined with expand=True, the widget grows to fill the parent container.

Answer

fill='all'

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fill='both'

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fill=tk.EXPAND

Question 3

To prevent a user from editing text in a widget, which configuration option should you set?

Accepted Answer

state=tk.DISABLED. Setting 'state' to 'disabled' prevents user interaction with the widget.

Answer

editable=False

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enabled=False

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readonly=True

Question 4

Which method on a widget instance causes it to be removed from the display, but not destroyed?

Accepted Answer

widget.pack_forget(). The pack_forget() (or grid_forget()) method hides a widget from the layout manager.

Answer

widget.hide()

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widget.remove()

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widget.delete()

Question 5

You want to trigger a function when a user releases a key. Which event string should you use with bind()?

Accepted Answer

. The '' event is used to detect when a key is released.

Answer

<Key-Up>

Answer

Answer

<KeyUp>

Question 6

Which THREE of the following are valid Tkinter variable classes used for tracking widget states?

Accepted Answer

IntVar. IntVar (B) is a valid Tkinter variable class that holds an integer value and is commonly bound to widgets like Entry or Scale to track and synchronize their state. StringVar (D) is likewise valid, storing a string value and used with widgets such as Entry, Label, and Text to reflect widget content. BooleanVar (E) is also valid, holding a boolean (0/1) value typically linked to Checkbutton widgets to track their checked state. The unmarked options do not belong: FloatVar (A) is not a real Tkinter class (the correct one is DoubleVar), and CharVar (C) does not exist in Tkinter's variable class set.

Answer

FloatVar

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CharVar

Question 7

Which TWO of the following statements about the 'grid' geometry manager are correct?

Accepted Answer

It allows widgets to span across multiple rows or columns.. Option C is correct because the grid geometry manager supports the rowspan and columnspan options, which let a widget occupy multiple adjacent rows or columns within its parent container. Option D is correct because grid positions widgets by specifying row and column indices (e.g., grid(row=0, column=1)), optionally combined with sticky, padx, and pady for alignment and spacing. Option A is wrong because grid uses relative cell-based placement rather than absolute pixel coordinates. Option B is wrong because grid supports arbitrary numbers of rows and columns, not just a single column. Option E is wrong because Tkinter permits mixing pack and grid within the same parent as long as they are not applied to widgets sharing the same master in conflicting ways; the restriction is about consistency, not an absolute prohibition.

Answer

It requires absolute pixel positioning.

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It only supports a single column layout.

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It cannot be mixed with the pack manager in the same parent.

Question 8

Which THREE of the following are valid states for a Tkinter widget?

Accepted Answer

disabled. In Tkinter, the widget 'state' option accepts a defined set of values, and the three valid states among the choices are 'disabled' (B), 'normal' (C), and 'active' (D). 'normal' (C) is the default state in which the widget responds to user interaction, such as a button being clickable. 'disabled' (B) makes the widget unresponsive and typically renders it greyed out, preventing any user input. 'active' (D) is the state a widget enters when the mouse pointer is over it (or during certain interactions), often used to change appearance via the 'activebackground' or 'activeforeground' options. The other options are not Tkinter widget states: 'readonly' (A) is a valid state for Tkinter Entry and Text widgets but is not a general widget state value, and 'hidden' (E) is not a state at all — visibility is controlled by the pack/grid/place geometry managers or the withdraw() method, not by the state option.

Answer

readonly

Answer

hidden

Question 9

You are building a Tkinter application and need to ensure that a Label widget expands to fill any extra horizontal space when the parent window is resized. Which configuration for the grid() layout manager achieves this?

Accepted Answer

parent.columnconfigure(0, weight=1) and widget.grid(sticky='ew'). The sticky parameter with 'ew' (east and west) ensures the widget stretches horizontally, while columnconfigure with weight > 0 allows the column to expand.

Answer

widget.pack(fill='x', expand=True)

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widget.grid(sticky='nsew')

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widget.grid(padx=10, pady=10)

Question 10

You are implementing a GUI where a long-running calculation is performed upon clicking a button. To prevent the GUI from freezing (not responding), what is the best practice approach?

Accepted Answer

Use the threading module to run the calculation in a separate thread.. Running blocking operations in the main thread freezes the event loop; threading is required to keep the GUI responsive.

Answer

Call root.update() inside the calculation loop.

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Increase the root.after() delay time.

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Wrap the calculation in a try-except block within the button command.

Answer

difficulty

Question 11

When binding an event to a widget using 'widget.bind('<Key>', handler)', the handler function receives an event object. How do you access the specific character pressed?

Accepted Answer

handler(event.char). The event object passed to the handler contains the 'char' attribute which holds the character pressed.

Answer

handler(event.keysym)

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handler(event.get_char())

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handler(event.key)

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difficulty

Question 12

You are using the pack() geometry manager and want to place a frame at the bottom of the window, ensuring it stays there even when other widgets are added. Which configuration is correct?

Accepted Answer

frame.pack(side='bottom', fill='x'). In Tkinter's pack geometry manager, the side option determines which side of the container the widget is packed against. Setting side='bottom' places the frame at the bottom of the window, and fill='x' makes it stretch horizontally to fill the available width. This configuration ensures the frame stays at the bottom even when other widgets are added, because pack allocates space in the order widgets are packed.

Answer

frame.pack(anchor='s', expand=True)

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frame.pack(side='bottom', expand=False)

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difficulty

Answer

frame.grid(row=99, column=0)

Question 13

Which widget is most appropriate if you need to display a read-only multi-line block of text to the user?

Accepted Answer

Text. The Text widget is standard for multi-line text, and setting 'state' to 'disabled' makes it read-only.

Answer

difficulty

Answer

Message

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Entry

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Label

Question 14

You want to create a Menu that contains sub-menus. Which class or method is used to add a sub-menu to an existing menu?

Accepted Answer

menu.add_cascade(). The add_cascade method is used to create a menu item that opens a sub-menu.

Answer

difficulty

Answer

menu.add_menu()

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menu.add_command()

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menu.add_submenu()

Question 15

Which TWO of the following methods are commonly used to update a Tkinter widget's state or appearance dynamically?

Accepted Answer

widget.config(state='disabled'). Option D is correct because Tkinter widgets expose the config() (aliased as configure()) method, and calling widget.config(state='disabled') dynamically changes the widget's state option at runtime, immediately updating its appearance and interactivity. Option E is correct because widget.insert(END, 'text') is the standard Tkinter method for dynamically adding content to text-bearing widgets such as Entry, Text, and Listbox, using the END index to append at the end. Options A, B, and C are not part of the Tkinter widget API: there is no rebind(), reload(), or refresh() method on standard Tkinter widgets, so they cannot be used to update a widget's state or appearance.

Answer

widget.rebind()

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widget.reload()

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widget.refresh()