---
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.
```python
@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.
```python
@st.experimental_fragment(run_every="10s")
def fragment():
df = get_data()
st.line_chart(df)
```
Rerun script
Rerun the script immediately.
```python
st.rerun()
```
Stop execution
Stops execution immediately.
```python
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.
```python
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.
```python
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](https://github.com/kmcgrady).
```python
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](https://github.com/lukasmasuch).
```python
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](https://github.com/blackary).
```python
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:"), ])
```