streamlit.py

import streamlit as st
import pandas as pd
import altair as alt
import urllib

from streamlit.server.server import Server
from streamlit.report_thread import get_report_ctx

@st.cache
def get_UN_data():
    AWS_BUCKET_URL = "https://streamlit-demo-data.s3-us-west-2.amazonaws.com"
    df = pd.read_csv(AWS_BUCKET_URL + "/agri.csv.gz")
    return df.set_index("Region")

try:
    df = get_UN_data()
    countries = st.multiselect(
        "Choose countries", list(df.index), ["China", "United States of America"]
    )

    min_elts, max_elts = st.slider("How many %ss (select a range)?" % "boop", 0, 25, [10, 20])
    if not countries:
        st.error("Please select at least one country.")
    else:
        data = df.loc[countries]
        data /= 1000000.0
        st.write("### Gross Agricultural Production ($B)", data.sort_index())

        data = data.T.reset_index()
        data = pd.melt(data, id_vars=["index"]).rename(
            columns={"index": "year", "value": "Gross Agricultural Product ($B)"}
        )
        chart = (
            alt.Chart(data)
            .mark_area(opacity=0.3)
            .encode(
                x="year:T",
                y=alt.Y("Gross Agricultural Product ($B):Q", stack=None),
                color="Region:N",
            )
        )
        st.altair_chart(chart, use_container_width=True)

        ctx = get_report_ctx()
        print(ctx.query_string)
        session_info = Server.get_current()._get_session_info(ctx.session_id)
        print(session_info.ws.request.headers)

        
        
except urllib.error.URLError as e:
    st.error(
        """
        **This demo requires internet access.**

        Connection error: %s
    """
        % e.reason
    )