designing-real-world-ai-agents-workshop: Skill for Claude Code

Streamlit selection widgets

The right selection widget for the job. Streamlit has evolved—many old patterns are now anti-patterns.

When to use what

Use st.segmented_control or st.pills when you want all options visible at once. Use st.selectbox or st.multiselect when options should be hidden in a dropdown.

Widget	Best For
st.segmented_control	2-5 options, single select, all visible
st.pills	2-5 options, multi-select, all visible
st.selectbox	Many options, single select, dropdown
st.multiselect	Many options, multi-select, dropdown

Segmented control (options visible, single select)

# BAD
status = st.radio("Status", ["Draft", "Published"], horizontal=True)

# GOOD
status = st.segmented_control("Status", ["Draft", "Published"])

For vertical layouts, st.radio(..., horizontal=False) is still a great choice.

Cleaner, more modern look than horizontal radio buttons.

Pills (options visible, multi-select)

# Multi-select with few options
selected = st.pills(
    "Tags",
    ["Python", "SQL", "dbt", "Streamlit"],
    selection_mode="multi"
)

Can also be used to mimic an "example" widget, especially with label_visibility="collapsed":

st.pills("Examples", ["Show me sales data", "Top customers"], label_visibility="collapsed")

More visual and easier to use than st.multiselect for small option sets.

Selectbox (many options, single select)

country = st.selectbox(
    "Select a country",
    ["USA", "UK", "Canada", "Germany", "France", ...]
)

Dropdowns scale better than radio/pills for long lists.

Multiselect (many options, multi-select)

countries = st.multiselect(
    "Select countries",
    ["USA", "UK", "Canada", "Germany", "France", ...]
)

Toggle vs checkbox

Use st.toggle for settings that trigger changes in the app. Reserve st.checkbox for forms.

# GOOD: Toggle for app settings
dark_mode = st.toggle("Dark mode")
show_advanced = st.toggle("Show advanced options")

# GOOD: Checkbox in forms
with st.form("signup"):
    agree = st.checkbox("I agree to the terms")
    st.form_submit_button("Sign up")