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Learn Streamlit

Turn Python scripts into interactive data apps with no front-end code

16 lessons · 3 hours · 4 levels · covers Streamlit 1.66

Streamlit is an open-source Python framework for building interactive web apps for data, machine learning and internal tools. You write a plain script with calls like st.slider and st.dataframe; Streamlit reruns it on every interaction and renders the result in the browser, with caching, session state, multipage navigation and chat elements built in.

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Before you start

Streamlit builds on these; the tree links to the exact lessons you need.

PythonEssentials levelpandasEssentials level

How deep do you want to go?

1. EssentialsRead and write simple code, do the everyday basics5 lessons · 52 min in total
2. PracticalUse it productively at work, with the usual idioms10 lessons · 2 hours in total
3. AdvancedThe less common features, performance and trade-offs13 lessons · 3 hours in total
4. ExpertInternals and the edge cases experts know16 lessons · 3 hours in total

The Streamlit tree

StreamlitScripts that rerun: the execution modelScripts that rerun: theexecution modelDisplaying text, data and metricsDisplaying text, dataand metricsInput widgetsInput widgetsCharts and mapsCharts and mapsLayout: sidebar, columns, tabs and containersLayout: sidebar,columns, tabs and…Caching with st.cache_data and st.cache_resourceCaching withst.cache_data and…Session state and callbacksSession state andcallbacksForms: batching inputForms: batchinginputMultipage apps with st.navigationMultipage apps withst.navigationSecrets and data connectionsSecrets and dataconnectionsRunning Python: REPL and scriptsRunning Python:REPL and scriptsDataFrameDataFrameDefining functionsDefining functionsIterators and generatorsIterators andgeneratorsTesting with pytest and unittestTesting with pytestand unittestThreads, processes and concurrent.futuresThreads, processesand concurrent.fut…
Essentials and Practical shown (10 of 16 lessons); the full list is below. Click a lesson to read it.

All 16 lessons, in order

The rerun model and basics

  1. Scripts that rerun: the execution model · Essentials · 10 min

    A Streamlit app is a Python script that reruns from top to bottom every time a user interacts with it.

  2. Displaying text, data and metrics · Essentials · 10 min

    Show text, Markdown, DataFrames, metrics, JSON and code with st.write and the dedicated display elements.

Widgets, charts and layout

  1. Input widgets · Essentials · 12 min

    Collect user input with buttons, sliders, text inputs, select boxes and file uploaders, and understand what each returns.

  2. Charts and maps · Essentials · 10 min

    Display charts with Streamlit's built-in chart elements or with Matplotlib, Plotly, Altair and other libraries.

  3. Layout: sidebar, columns, tabs and containers · Essentials · 10 min

    Arrange elements with the sidebar, columns, tabs, expanders, containers and placeholders, and configure the page.

State, caching and forms

  1. Caching with st.cache_data and st.cache_resource · Practical · 14 min

    Avoid repeating slow work on every rerun by caching data results and shared resources, with TTLs and invalidation.

  2. Session state and callbacks · Practical · 14 min

    Keep values across reruns with st.session_state, link it to widget keys, and react to changes with on_change and on_click callbacks.

  3. Forms: batching input · Practical · 10 min

    Group widgets in st.form so the app reruns only when the user submits, not on every change.

  4. Fragments, dialogs and controlling reruns · Advanced · 14 min

    Rerun only part of a page with st.fragment, refresh it on a timer, open modal dialogs, and trigger reruns with st.rerun.

Multipage and real apps

  1. Multipage apps with st.navigation · Practical · 12 min

    Split an app into pages with st.Page and st.navigation, group them in sections, and link or switch between pages.

  2. Secrets and data connections · Practical · 12 min

    Store credentials in secrets.toml, read them with st.secrets, and query databases and APIs with st.connection.

  3. Chat and LLM apps · Advanced · 12 min

    Build conversational interfaces with st.chat_message, st.chat_input and st.write_stream, keeping history in session state.

Testing and production

  1. Testing apps with AppTest · Advanced · 12 min

    Write fast, headless tests for Streamlit apps with streamlit.testing.v1.AppTest and pytest.

  2. Configuration, deployment and authentication · Expert · 15 min

    Configure apps with config.toml, deploy to Community Cloud or containers, add OIDC login with st.login, and plan for scaling.

Architecture and extending

  1. Architecture: sessions, threads and reruns · Expert · 16 min

    Understand how the Streamlit server, sessions, script threads, widget IDs and caches interact, to debug subtle bugs and design scalable apps.

  2. Custom components · Expert · 14 min

    Extend Streamlit with your own HTML, CSS and JavaScript using st.html and st.components.v2, exchanging data with Python.