Data manipulation in Streamlit

Streamlit runs our Python file from the top down as a script, so we can perform data manipulation with powerful libraries such as pandas in the same way that we might in a Jupyter notebook or a regular Python script. As we’ve discussed before, we can do all our regular data manipulation as normal. For our Palmer’s Penguins app, what if we wanted the user to be able to filter out penguins based on their gender? The following code filters our DataFrame using pandas:

import streamlit as st
import pandas as pd
import altair as alt 
import seaborn as sns
st.title("Palmer's Penguins")
st.markdown('Use this Streamlit app to make your own scatterplot about penguins!')
penguin_file = st.file_uploader(
    'Select Your Local Penguins CSV (default provided)')
if penguin_file is not None:
    penguins_df = pd.read_csv(penguin_file)
else:
    penguins_df = pd.read_csv('penguins.csv')
selected_x_var =...