在ipywidget.textarea中更改字体大小

from ipywidgets import Textarea, Layout
from IPython.display import display

textarea = Textarea(value='这是一个文本框', layout=Layout(width='500px', height='200px'))

def change_font_size(font_size):
    textarea.style.font_size = font_size

font_size_dropdown = Dropdown(options=['12px', '14px', '16px', '18px'], value='12px', description='字体大小:')

font_size_dropdown.observe(lambda change: change_font_size(change['new']), names='value')

display(textarea, font_size_dropdown)