Bird
0
0

What will be the value of the variable pressed after clicking the button in this code snippet?

medium📝 Predict Output Q5 of 15
Matplotlib - Interactive Features
What will be the value of the variable pressed after clicking the button in this code snippet?
import matplotlib.pyplot as plt
from matplotlib.widgets import Button

fig, ax = plt.subplots()
button_ax = plt.axes([0.8, 0.05, 0.1, 0.075])
button = Button(button_ax, 'Press')

pressed = False
def on_press(event):
    global pressed
    pressed = True

button.on_clicked(on_press)
button.eventson = True

# Simulate a button click here
button._click(event=None)
print(pressed)
ATrue
BFalse
CNone
DRaises an error
Step-by-Step Solution
Solution:
  1. Step 1: Understand the Button and Callback

    The button is linked to the on_press function, which sets pressed to True when clicked.
  2. Step 2: Simulate the Button Click

    The code calls button._click(event=None) to simulate a click, triggering the callback.
  3. Step 3: Check the Printed Value

    After the simulated click, pressed is set to True, so printing it outputs True.
  4. Final Answer:

    True -> Option A
  5. Quick Check:

    Callback changes variable on click [OK]
Quick Trick: Button callbacks update variables on click [OK]
Common Mistakes:
  • Forgetting to connect the callback with on_clicked
  • Assuming _click method does not trigger callbacks
  • Not setting eventson to True

Want More Practice?

15+ quiz questions · All difficulty levels · Free

Free Signup - Practice All Questions
More Matplotlib Quizzes