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(aparam):
	adf2 = aparam[0]["adataframe"]
	astationcode = adf2.loc[adf2["atitle"]==aparam[0]["aselected"]]['astationcode']
	acontainer3.write(astationcode)
adf = pd.DataFrame(
	astations,
	columns=astationcolumns
)
aoption = acontainer1.selectbox(
	'Which station?',
	adf['atitle']
)
acontainer2.button("Submit",on_click=asubmit,args=[{'aselected':aoption,'adataframe':adf,'adummy':None,}])