How to set page config default layout to wide without calling set_page_config?

Using Streamlit
1

I am facing this issue when trying to set page config in a multi-page app. The multi-page app is from here.

I have an idea of setting the default layout to wide which will solve my issue but how to do so?

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

2

Hi @Keeb_Thock, welcome to the community!

I was facing a similar issue,
Below solved the issue is my case:

in your main.py file, add the page config to the state object.

import streamlit as st

from SessionState import _get_state


state = _get_state()

state.page_config = st.set_page_config(
    page_title="BPJV SI Database Manager test",
    layout="wide",
    initial_sidebar_state="expanded",
)

# rest of the code

state.sync()
3

Where did you get your SessionState? @maarten-betman
Can I have a look at the full code of SessionState? The one I used is different and even after adding your suggestion, the same error still appears.

import streamlit as st
import pandas as pd
from pages import login, signup, custom_model # import your app modules here
from db_func import *
from session_state import _get_state

# Hide mainmenu and footer
hide_streamlit_style = """
            <style>
            #MainMenu {visibility: hidden;}
            footer {visibility: hidden;}
            </style>
            """
st.markdown(hide_streamlit_style, unsafe_allow_html=True)



def main():
    state = _get_state()

    state.page_config = st.set_page_config(page_title="ABC", layout="wide", initial_sidebar_state="expanded")

    pages = {
        "Login": login.app,
        "Signup": signup.app,
        "Custom Model": custom_model.app,
    }

    st.sidebar.title(":floppy_disk: Page states")
    page = st.sidebar.selectbox("Select Page", tuple(pages.keys()))

    # Display the selected page with the session state
    pages[page](state,st)
    
    # Mandatory to avoid rollbacks with widgets, must be called at the end of your app
    state.sync()

if __name__ == "__main__":
    main()
4

Got it from this gist:

If the problem persists you can try to remove the __name__ == "__main__" block.
Shouldn’t be required in your main page file when you run streamlit.

5

@maarten-betman There is no _get_state though from the gist you linked.

6

Yes, must have been another gist. Can’t find the original gist.
Anyway, I just uploaded my SessionState.py as gist.

1 Like
7

Even after I use your SessionState and removing __name__ == "__main__", I am still facing the same error.

import streamlit as st
import pandas as pd
from pages import login, signup, custom_model # import your app modules here
from db_func import *
from session_state import _get_state

# Hide mainmenu and footer
hide_streamlit_style = """
            <style>
            #MainMenu {visibility: hidden;}
            footer {visibility: hidden;}
            </style>
            """
st.markdown(hide_streamlit_style, unsafe_allow_html=True)



""" def main():
    state = _get_state()
    #state.stock_list=[]
    state(stock_list=[])
    state.page_config = st.set_page_config(page_title="WhaleBot - Bursa Robo-Advisor", layout="wide", initial_sidebar_state="expanded")

    pages = {
        "Login": login.app,
        "Signup": signup.app,
        "Custom Model": custom_model.app,
    }

    st.sidebar.title(":floppy_disk: Page states")
    page = st.sidebar.selectbox("Select Page", tuple(pages.keys()))

    # Display the selected page with the session state
    pages[page](state,st)
    
    # Mandatory to avoid rollbacks with widgets, must be called at the end of your app
    state.sync()

if __name__ == "__main__":
    main() """

state = _get_state()
#state.stock_list=[]
state(stock_list=[])
state.page_config = st.set_page_config(page_title="ABC", layout="wide", initial_sidebar_state="expanded")

pages = {
    "Login": login.app,
    "Signup": signup.app,
    "Custom Model": custom_model.app,
}

st.sidebar.title(":floppy_disk: Page states")
page = st.sidebar.selectbox("Select Page", tuple(pages.keys()))

# Display the selected page with the session state
pages[page](state,st)

# Mandatory to avoid rollbacks with widgets, must be called at the end of your app
state.sync()
8

My next guess will be the way you navigate between multiple pages might be different from my approach. Any idea? @maarten-betman

9

I follow a similar pattern, so can’t help you any further sorry.

Last things you could look at:
I call _get_state and the page_config directly after the imports.

Add the empty list to the state object like this:
state.stock_list = []

10

Wow, my initial code works too as long as I move the code related to hiding mainmenu and footer to the bottom. Lol… Thanks @maarten-betman for your help

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