app.py

import streamlit as st
import pandas as pd

astations = [
	["hongkongobservatory","HKO",22.3022566,114.1722662,"Hong Kong Observatory"],
	["kingspark","KP",22.3115408,114.1685675,"Observatory Meteorological Station, King's Park"],
]
astationcolumns = ['akey','astationcode','alatitude','alongitude','atitle',]

acontainer1 = st.empty()
acontainer2 = st.empty()
acontainer3 = st.empty()

def asubmit(aselected="",acontainer=None,adataframe=pd.DataFrame()):
	acontainer.write((" {} ").format(aselected))

adf = pd.DataFrame(
	astations,
	columns=astationcolumns
)
aoption = acontainer1.selectbox(
	'Which station?',
	adf['atitle']
)
if acontainer2.button("Submit",on_click=asubmit) == True:
	asubmit({"aselected":aoption,"acontainer":acontainer3,"adataframe":adf,})