This course will teach you how to develop web apps using the Streamlit library. With just a few lines of code, you can have your app up and running in no time.

streamlit.tar.gz

Streamlit

This course will teach you how to develop web apps using the Streamlit library. With just a few lines of code, you can have your app up and running in no time.

We'll start off with learning about the various components of Streamlit, before finally building an app that you can deploy and have your users access.

Develop Web Apps with Streamlit

Each time your app runs, the variables are all initialzed again, since the script runs from top to bottom each time a change occurs (refreshing the page, widget value changes, etc). Should you wish to have certain variables unchanged in between runs, then use the st.session_state() method.

The following code helps illustrate the difference between saving state and not doing so.

delta = None
step = 0.5

humidity = 75.0

raise_humidity = st.button("Raise humidity")
if raise_humidity:
    humidity += step
st.metric("The humidity is: ", humidity, delta)

if "temperature" not in st.session_state:
    st.session_state["temperature"] = 25.0

raise_temperature = st.button("Raise temperature")
if raise_temperature:
    st.session_state["temperature"] += step
    delta = step
lower_temperature = st.button("Lower temperature")
if lower_temperature:
    st.session_state["temperature"] -= step
    delta = -step

st.metric("The temperature is: ", st.session_state["temperature"], delta)

When you click the button to raise humidity, past the first increment, nothing more happens, and the value remains at 75.5. But for temperature, each button press, up or down, results in the value changing. You also notice that when you press the temperature buttons, the value of humidity is reset to 75, again because each run of the app means the script is executed from top to bottom.

First Things First

Introduction to Streamlit

Display Information with Streamlit

Display Interactive Widgets with Streamlit

Streamlit Layout

Mutate Data with Streamlit

Streamlit Miscallenous Items

Deploy Streamlit Apps

Streamlit Session State