metadata

title: Execution flow
slug: /develop/api-reference/execution-flow

Execution flow

Change execution

By default, Streamlit apps execute the script entirely, but we allow some functionality to handle control flow in your applications.

Modal dialogs

Insert a modal dialog that can rerun independently from the rest of the script.

@st.experimental_dialog()
def email_form():
    name = st.text_input("Name")
    email = st.text_input("Email")

Partial reruns

Define a fragment to rerun independently from the rest of the script.

@st.experimental_fragment(run_every="10s")
def fragment():
    df = get_data()
    st.line_chart(df)

Rerun script

Rerun the script immediately.

st.rerun()

Stop execution

Stops execution immediately.

st.stop()

Group multiple widgets

By default, Streamlit reruns your script everytime a user interacts with your app. However, sometimes it's a better user experience to wait until a group of related widgets is filled before actually rerunning the script. That's what st.form is for!

Forms

Create a form that batches elements together with a “Submit" button.

with st.form(key='my_form'):
    name = st.text_input("Name")
    email = st.text_input("Email")
    st.form_submit_button("Sign up")

Form submit button

Display a form submit button.

with st.form(key='my_form'):
    name = st.text_input("Name")
    email = st.text_input("Email")
    st.form_submit_button("Sign up")

Autorefresh

Force a refresh without tying up a script. Created by @kmcgrady.

from streamlit_autorefresh import st_autorefresh

st_autorefresh(interval=2000, limit=100,
  key="fizzbuzzcounter")

Pydantic

Auto-generate Streamlit UI from Pydantic Models and Dataclasses. Created by @lukasmasuch.

import streamlit_pydantic as sp

sp.pydantic_form(key="my_form",
  model=ExampleModel)

Streamlit Pages

An experimental version of Streamlit Multi-Page Apps. Created by @blackary.

from st_pages import Page, show_pages, add_page_title

show_pages([ Page("streamlit_app.py", "Home", "🏠"),
  Page("other_pages/page2.py", "Page 2", ":books:"), ])