Overwriting elements in-place using "with" notation:

>>> import time
>>>
>>> with st.empty():
...     for seconds in range(60):
...         st.write(f"⏳ {seconds} seconds have passed")
...         time.sleep(1)
...     st.write("✔️ 1 minute over!")

Replacing several elements, then clearing them:

>>> placeholder = st.empty()
>>>
>>> # Replace the placeholder with some text:
>>> placeholder.text("Hello")
>>>
>>> # Replace the text with a chart:
>>> placeholder.line_chart({"data": [1, 5, 2, 6]})
>>>
>>> # Replace the chart with several elements:
>>> with placeholder.container():
...     st.write("This is one element")
...     st.write("This is another")
...
>>> # Clear all those elements:
>>> placeholder.empty()