Streamlit API cheat sheet

This is a summary of the docs, as of Streamlit v1.35.0.

Install & Import

pip install streamlit streamlit run # Import convention >>> import streamlit as st

Pre-release features

pip uninstall streamlit pip install streamlit-nightly --upgrade

Learn more about experimental features

Command line

streamlit --help streamlit run streamlit hello streamlit config show streamlit cache clear streamlit docs streamlit --version

Magic commands

# Magic commands implicitly # call st.write(). "_This_ is some **Markdown***" my_variable "dataframe:", my_data_frame

Display text

st.write("Most objects") # df, err, func, keras! st.write(["st", "is <", 3]) # see * st.write_stream(my_generator) st.write_stream(my_llm_stream) st.text("Fixed width text") st.markdown("_Markdown_") # see * st.latex(r""" e^{i\pi} + 1 = 0 """) st.title("My title") st.header("My header") st.subheader("My sub") st.code("for i in range(8): foo()") st.html("<p>Hi!</p>")

Display data

st.dataframe(my_dataframe) st.table(data.iloc[0:10]) st.json({"foo":"bar","fu":"ba"}) st.metric("My metric", 42, 2)

Display media

st.image("./header.png"), subtitles="./subs.vtt") st.logo("logo.jpg")

Display charts

st.area_chart(df) st.bar_chart(df) st.bar_chart(df, horizontal=True) st.line_chart(df) st.scatter_chart(df) st.altair_chart(chart) st.bokeh_chart(fig) st.graphviz_chart(fig) st.plotly_chart(fig) st.pydeck_chart(chart) st.pyplot(fig) st.vega_lite_chart(df, spec) # Work with user selections event = st.plotly_chart( df, on_select="rerun" ) event = st.altair_chart( chart, on_select="rerun" ) event = st.vega_lite_chart( df, spec, on_select="rerun" )

Add elements to sidebar

# Just add it after st.sidebar: a ="Select one:", [1, 2]) # Or use "with" notation: with st.sidebar:"Select one:", [1, 2])


# Two equal columns: col1, col2 = st.columns(2) col1.write("This is column 1") col2.write("This is column 2") # Three different columns: col1, col2, col3 = st.columns([3, 1, 1]) # col1 is larger. # Bottom-aligned columns col1, col2 = st.columns(2, vertical_alignment="bottom") # You can also use "with" notation: with col1:"Select one:", [1, 2])


# Insert containers separated into tabs: tab1, tab2 = st.tabs(["Tab 1", "Tab2"]) tab1.write("this is tab 1") tab2.write("this is tab 2") # You can also use "with" notation: with tab1:"Select one:", [1, 2])

Expandable containers

expand = st.expander("My label", icon=":material/info:") expand.write("Inside the expander.") pop = st.popover("Button label") pop.checkbox("Show all") # You can also use "with" notation: with expand:"Select one:", [1, 2])

Control flow

# Stop execution immediately: st.stop() # Rerun script immediately: st.rerun() # Navigate to another page: st.switch_page("pages/") # Define a navigation widget in your entrypoint file pg = st.navigation( st.Page("", title="Home", url_path="home", default=True) st.Page("", title="Preferences", url_path="settings") ) # Group multiple widgets: with st.form(key="my_form"): username = st.text_input("Username") password = st.text_input("Password") st.form_submit_button("Login") # Define a dialog function @st.experimental_dialog("Welcome!") def modal_dialog(): st.write("Hello") modal_dialog() # Define a fragment @st.experimental_fragment def fragment_function(): df = get_data() st.line_chart(df) st.button("Update") fragment_function()

Display interactive widgets

st.button("Click me") st.download_button("Download file", data) st.link_button("Go to gallery", url) st.page_link("", label="Home") st.data_editor("Edit data", data) st.checkbox("I agree") st.toggle("Enable")"Pick one", ["cats", "dogs"]) st.selectbox("Pick one", ["cats", "dogs"]) st.multiselect("Buy", ["milk", "apples", "potatoes"]) st.slider("Pick a number", 0, 100) st.select_slider("Pick a size", ["S", "M", "L"]) st.text_input("First name") st.number_input("Pick a number", 0, 10) st.text_area("Text to translate") st.date_input("Your birthday") st.time_input("Meeting time") st.file_uploader("Upload a CSV") st.camera_input("Take a picture") st.color_picker("Pick a color") # Use widgets' returned values in variables: for i in range(int(st.number_input("Num:"))): foo() if st.sidebar.selectbox("I:",["f"]) == "f": b() my_slider_val = st.slider("Quinn Mallory", 1, 88) st.write(slider_val) # Disable widgets to remove interactivity: st.slider("Pick a number", 0, 100, disabled=True)

Build chat-based apps

# Insert a chat message container. with st.chat_message("user"): st.write("Hello ๐Ÿ‘‹") st.line_chart(np.random.randn(30, 3)) # Display a chat input widget at the bottom of the app. >>> st.chat_input("Say something") # Display a chat input widget inline. with st.container(): st.chat_input("Say something")

Learn how to Build a basic LLM chat app

Mutate data

# Add rows to a dataframe after # showing it. element = st.dataframe(df1) element.add_rows(df2) # Add rows to a chart after # showing it. element = st.line_chart(df1) element.add_rows(df2)

Display code

with st.echo(): st.write("Code will be executed and printed")

Placeholders, help, and options

# Replace any single element. element = st.empty() element.line_chart(...) element.text_input(...) # Replaces previous. # Insert out of order. elements = st.container() elements.line_chart(...) st.write("Hello") elements.text_input(...) # Appears above "Hello". st.get_option(key) st.set_option(key, value) st.set_page_config(layout="wide") st.query_params[key] st.query_params.from_dict(params_dict) st.query_params.get_all(key) st.query_params.clear() st.html("<p>Hi!</p>")

Connect to data sources

st.connection("pets_db", type="sql") conn = st.connection("sql") conn = st.connection("snowflake") class MyConnection(BaseConnection[myconn.MyConnection]): def _connect(self, **kwargs) -> MyConnection: return myconn.connect(**self._secrets, **kwargs) def query(self, query): return self._instance.query(query)

Optimize performance

Cache data objects
# E.g. Dataframe computation, storing downloaded data, etc. @st.cache_data def foo(bar): # Do something expensive and return data return data # Executes foo d1 = foo(ref1) # Does not execute foo # Returns cached item by value, d1 == d2 d2 = foo(ref1) # Different arg, so function foo executes d3 = foo(ref2) # Clear the cached value for foo(ref1) foo.clear(ref1) # Clear all cached entries for this function foo.clear() # Clear values from *all* in-memory or on-disk cached functions st.cache_data.clear()
Cache global resources
# E.g. TensorFlow session, database connection, etc. @st.cache_resource def foo(bar): # Create and return a non-data object return session # Executes foo s1 = foo(ref1) # Does not execute foo # Returns cached item by reference, s1 == s2 s2 = foo(ref1) # Different arg, so function foo executes s3 = foo(ref2) # Clear the cached value for foo(ref1) foo.clear(ref1) # Clear all cached entries for this function foo.clear() # Clear all global resources from cache st.cache_resource.clear()

Display progress and status

# Show a spinner during a process with st.spinner(text="In progress"): time.sleep(3) st.success("Done") # Show and update progress bar bar = st.progress(50) time.sleep(3) bar.progress(100) with st.status("Authenticating...") as s: time.sleep(2) st.write("Some long response.") s.update(label="Response") st.balloons() st.snow() st.toast("Warming up...") st.error("Error message") st.warning("Warning message")"Info message") st.success("Success message") st.exception(e)

Personalize apps for users

# Show different content based on the user's email address. if == "": display_jane_content() elif == "": display_adam_content() else: st.write("Please contact us to get access!")

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