import numpy as np
import pandas as pd
import streamlit as st


@st.cache_data
def load_data():
    df = pd.DataFrame({
        'col1' : np.random.randn(20),
        'col2' : np.random.randn(20),
        'col3' : np.random.choice(['A','B','C'], 20)
    })
    return df


chart_data = load_data()

st.line_chart(
    chart_data,
    x = 'col1',
    y = 'col2',
    color = 'col3'
)