How can i pause this code in Jupyter Notebook?

Question

When i click the Submit answer button, additional codes can only be run after that.

import ipywidgets as widgets

Here are a few lines of code that are responsible for the look of the button etc.

selector = widgets.RadioButtons(
    options=['Valid', 'Invalid', 'Skip'], 
    value=None,
    description='',
    disabled=False
)
button = widgets.Button(
    description='Submit answer',
    disabled=False,
    button_style='',
)
    
def evaluate(button):
    selection = selector.get_interact_value()    
    if (selection == 'Valid'):
        f = open(r"C:\Users\asd\Desktop\asd.txt", "a", encoding='utf-8')
        f.write('asd')
        f.close()
    elif (selection == 'Invalid'):
        pass
    elif (selection == 'Skip'):
        pass

button.on_click(evaluate)        

left_box = widgets.VBox([selector, button])
widgets.HBox([left_box])

print('nvm') **#If I click Submit answer button, then run this code**

How can i do that?

Answer 1

a simple trick to do that (without doing an empty while loop that will abuse your cpu) is to put your code in a sleep loop untill the button is pressed.

answer_pressed = False
def evaluate(button):
    global answer_pressed 
    answer_pressed = True
    # rest of function here

button.on_click(evaluate)        

import time
while answer_pressed == False: # put the interpreter to sleep until the button is pressed.
    time.sleep(0.01) # or 0.1 depending on the required resposivity.

Edit : you might want to move the answer_pressed = True to the end of the function instead of the beginning, so you will be sure the function has executed fully before breaking the while loop.