Trying to make a drop down list of States and then cities based on state selected by user. Problem with dict and what's displayed

Question

I am doing a project in streamlit, where I am making a drop-down list of every state, then based on the selected state, the city drop-down box will only show cities from that state. My problem is that my values for states goes like {'full name of state': 'state abbreviation'}. The cities' data only has city and state abbreviation, so when I check to see if the option is selected, I can only show the abbreviations.

import streamlit as st
import geonamescache

states_dict = dict()
cs = ["Select a city"]

col1, col2, col3 = st.columns(3)

with col2:
    gc = geonamescache.GeonamesCache()
    city = gc.get_cities()
    states = gc.get_us_states()

    if "disabled" not in st.session_state:
        st.session_state.disabled = True

    def callback():
        st.session_state.disabled = False

    # ---STATES---
    
    for state, code in states.items():
        states_dict[code['name']] = state

    option_s = st.selectbox("Select a State", states_dict.items())

    if option_s == "Select a State":
        st.write("#")
    else:
        st.write("You selected:", option_s)

    # ---CITIES---

    for city in city.values():
        if city['countrycode'] == 'US':
            if city['admin1code'] == option_s[1]:
                cs.append(city['name'])

    option_c = st.selectbox("Select a city", cs, disabled=st.session_state.disabled, on_change=callback())

    if option_c == "Select a city":
        st.write("#")
    else:
        st.write("You selected:", option_c)

Right now I have it showing both values from the Dictionary, but I'm trying to get it for example to just be California in the state and show every city from california matching CA from states_dict to city['admin1code'].

Answer 1

Does this work as you want:

if "disabled" not in st.session_state:
    st.session_state.disabled = True


def callback():
    st.session_state.disabled = False


states_dict = dict()
cs = ["Select a city"]

col1, col2, col3 = st.columns(3)

with col2:
    gc = geonamescache.GeonamesCache()
    city = gc.get_cities()
    states = gc.get_us_states()

    # ---STATES---

    for state, code in states.items():
        states_dict[code["name"]] = state

    option_s = st.selectbox("Select a State", states_dict.keys())

    if option_s == "Select a State":
        st.write("#")
    else:
        st.write("You selected:", option_s)

    # ---CITIES---

    for city in city.values():
        if city["countrycode"] == "US":
            if city["admin1code"] == states_dict[option_s]:
                cs.append(city["name"])

    option_c = st.selectbox("Select a city", cs, disabled=st.session_state.disabled, on_change=callback())

    if option_c == "Select a city":
        st.write("#")
    else:
        st.write("You selected:", option_c)

What changed is that only keys() are displayed in the states dictionary, so that abbreviations are not displayed. Then the states_dict is called again to check the abbreviation equality with the option selected.

Otherwise I just extracted the callback and the disabled option from the with statement, but this should have no effect.