     np.random.randn(20, 3),
     columns=['a', 'b', 'c'])
st.line_chart(chart_data)
```
Plot a map
With st.map() you can display data points on a map.
Let's use Numpy to generate some sample data and plot it on a map of
San Francisco.
```python
import streamlit as st
import numpy as np
import pandas as pd
map_data = pd.DataFrame(
    np.random.randn(1000, 2) / [50, 50] + [37.76, -122.4],
    columns=['lat', 'lon'])
st.map(map_data)
```
Widgets
When you've got the data or model into the state that you want to explore, you
can add in widgets like st.slider(),
st.button() or
st.selectbox(). It's really straightforward
— treat widgets as variables:
python
import streamlit as st
x = st.slider('x')  # 👈 this is a widget
st.write(x, 'squared is', x * x)
On first run, the app above should output the text "0 squared is 0". Then
