When you are editing a Streamlit app, Always Rerun lets you save your Python file and see the updated app in the browser without clicking Rerun each time. Start the app once with `streamlit run <filename>`; you do not need to repeat that terminal command after ordinary code edits. section 2.4 section 2.5.5
Choose how you want to review changes:
- Save the file and click Rerun when Streamlit reports that the source changed. This gives you control over when the new version appears. section 2.5.5
- Click Always Rerun to have Streamlit update the app automatically after code changes. To turn it off, open the upper-right menu, select Settings, and uncheck Run on Save. section 2.5.5
Check a password-rule change
Add a rule requiring a numeral and edit the password-check button’s label. After saving, use Rerun or Always Rerun to see the new label and test the new rule in the browser. section 2.5.5
Always Rerun is a development setting for code changes, not a requirement for widget interactions: clicking a button or changing a selection already reruns the Python script. Automatic updates can also make it harder to spot what changed on the page. Changes to files or databases the app depends on may occasionally require stopping and restarting the app. section 2.5.5 section 4.3.2 section 2.4
