In order to display a message and then later on, remove it and replace it with another html message.
from IPython.core.display import display, clear_output
from IPython.core.display import HTML
...
display(HTML('<span style="font-size: 20px; color:blue">Work in progress ... </span>'))
...
clear_output(wait=False)
display(HTML('<span style="font-size: 20px; color:blue">Done!</span>'))
