Page_icon & Title not showing on subpages

[Vince_Fleming]

Summary

With an app that has multiple pages (pages/ directory), the set_page_config(page_icon='my_favicon.ico') only works on the base page. All other pages (everything in pages/) get a streamlit icon or no icon at all (world).

Steps to reproduce

Base page… icon_test1.py

import streamlit as st

st.set_page_config(page_title="Icon Test Main", page_icon='favicon.ico',
                   layout="wide", menu_items=None)

st.markdown("## Base Page")

pages/1_page1.py:

import streamlit as st

st.markdown("## Page 1")

Run the app and move between the pages and observe the page icon and title in the browser tab.

Expected behavior:

Since we’re not supposed to use set_page_config() more than once in the entire app, I would expect it to apply to all pages, not just the base page.

Actual behavior:

The page_icon displays either a streamlit icon or a “world” on all subpages, title changes to default title on subpages.
Suggested fix would be to either allow the set_page_config() on all pages, or have the settings apply globally.

Debug info

• Streamlit version: streamlit-1.21.0
• Python version: Python 3.8.12
• Using Conda? PipEnv? PyEnv? Pex? No.
• OS version: Rocky Linux 8.6 and MacOS 12.3
• Browser version: Chrome Version 112.0.5615.49 (Official Build) (arm64)

Requirements file

Just streamlit. I would provide my favicon.ico file, but I don’t see how to upload it.

Links

[mathcatsand]

I tested it with an emoji as well and the last several versions all did this. I took a quick peek on GitHub and I don’t see exactly this issue recorded as an open bug report yet. I believe you can report it as a bug. I agree with your logic that if st.set_page_config is meant to be called first and only once then I would expect the icon to carry over to other pages in the same way layout='wide' does.

[Vince_Fleming]

@Vince_Fleming

Chrome Version 112.0.5615.49 (Official Build) (arm64)

Page_icon & Title not showing on subpages · Issue #6572 · streamlit/streamlit · GitHub created.

[blackary]

I don’t see anything in the documentation st.set_page_config - Streamlit Docs that would indicate that if you use it on one page it carries across multiple pages. As far as I know, the fact that it works with layout=wide is not necessarily an intended behavior. My understanding is that the phrase “and must only be set once” simply applies to a single page, not to an entire multipage app.

That being said, this is certainly a reasonable feature request. But, for now, the easy solution is to call st.set_page_config at the top of each page.

[mathcatsand]

Ah! I see the confusion. The docs say about set_page_config:

This must be the first Streamlit command used in your app, and must only be set once.

This line reads to me on a per app basis rather than a per page basis. My brain made an assumption between that line and the fact that layout carried over that set_page_config was meant as a first line on your app’s main page specifically.

I think a simple edit here along the lines:

This must be the first Streamlit command used on an app page, and must only be set once per page.

[Vince_Fleming]

…except this happens if you put it on every page:

Apr 26 10:09:25 weka-beta-os.localdomain start_gui[7213]: Traceback (most recent call last):
Apr 26 10:09:25 weka-beta-os.localdomain start_gui[7213]:   File "/opt/gui/venv/lib64/python3.11/site-packages/streamlit/runtime/scriptrunner/script_runner.py", line 565, in _run_script
Apr 26 10:09:25 weka-beta-os.localdomain start_gui[7213]:     exec(code, module.__dict__)
Apr 26 10:09:25 weka-beta-os.localdomain start_gui[7213]:   File "/opt/gui/pages/5_Edit_Hosts_File.py", line 10, in <module>
Apr 26 10:09:25 weka-beta-os.localdomain start_gui[7213]:     st.set_page_config(page_title="WEKA Management Station Config", page_icon='favicon.ico',
Apr 26 10:09:25 weka-beta-os.localdomain start_gui[7213]:   File "/opt/gui/venv/lib64/python3.11/site-packages/streamlit/runtime/metrics_util.py", line 311, in wrapped_func
Apr 26 10:09:25 weka-beta-os.localdomain start_gui[7213]:     result = non_optional_func(*args, **kwargs)
Apr 26 10:09:25 weka-beta-os.localdomain start_gui[7213]:              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Apr 26 10:09:25 weka-beta-os.localdomain start_gui[7213]:   File "/opt/gui/venv/lib64/python3.11/site-packages/streamlit/commands/page_config.py", line 225, in set_page_config
Apr 26 10:09:25 weka-beta-os.localdomain start_gui[7213]:     ctx.enqueue(msg)
Apr 26 10:09:25 weka-beta-os.localdomain start_gui[7213]:   File "/opt/gui/venv/lib64/python3.11/site-packages/streamlit/runtime/scriptrunner/script_run_context.py", line 90, in enqueue
Apr 26 10:09:25 weka-beta-os.localdomain start_gui[7213]:     raise StreamlitAPIException(
Apr 26 10:09:25 weka-beta-os.localdomain start_gui[7213]: streamlit.errors.StreamlitAPIException: `set_page_config()` can only be called once per app, and must be called as the first Streamlit command in your script.
Apr 26 10:09:25 weka-beta-os.localdomain start_gui[7213]: For more information refer to the [docs](https://docs.streamlit.io/library/api-reference/utilities/st.set_page_config).

“set_page_config() can only be called once per app, and must be called as the first Streamlit command in your script.”

[blackary]

@Vince_Fleming Can you share your whole repo? It could be something else you are doing on the 5_edit_hosts_file.py that is also calling st.set_page_config somehow.

[Vince_Fleming]

It’s a little complicated… I’m using some wheels that I had to make some customizations to, so you would likely have some issues with dependencies. I’ll take some more time to review myself, and if I can’t resolve it, I’ll respond here with the github link.