How can I access st.title in a st.container() with AppTest?

🎈 Using Streamlit
1

I have this section in streamlit_app.py:

import streamlit as st

col1, col = st.columns((1, 1))
with st.container():
    col1.title("My App")

and I am trying to use AppTest to test that st.title is equal to “My App” but I can’t seem to access it with my test file:

from streamlit.testing.v1 import AppTest

at = AppTest.from_file("graph.py", default_timeout=75).run()

def test_headers():
    assert "My App" in at.container[0].columns[0].title[0].value

I can’t seem to find it in the docs on how to access the container. I know there is this section, retrieve containers, but, at least to me, it’s not super clear how to access elements in a container. An example like this in the docs would be nice. The cheatsheet for layouts and containers doesn’t to have an example for containers except for sidebar, columns, and tabs.

2

The columns are not inside a container.

3

Okay… @Goyo
This still doesn’t work:

import streamlit as st

with st.container():
    col1, col = st.columns((1, 1))
    col1.title("My App")
4

Well, now the columns are inside a container, but they are still accesible in at.columns.

5

@Goyo either way, I can’t seem to get pytest to pass the test so I am still not sure what I am doing wrong and what I need to do.

This passes:

test file:

from streamlit.testing.v1 import AppTest

at = AppTest.from_file("graph.py", default_timeout=75).run()

def test_headers():
    assert "My App" in at.columns[0].title[0].value

streamlit file:

import streamlit as st

col1, col2 = st.columns((9, 1))
col1.title("My App")

This fails:

but the moment I put the streamlit file code in a container, it fails:

import streamlit as st

with st.container():
    col1, col2 = st.columns((9, 1))
    col1.title("My App")

so it doesn’t seem to that they are accessible in at.columns like you mentioned unless I’m missing something.

6

Weird, both versions of the code pass the test for me.

7

Really? That’s strange… maybe some dependency issue? What version of Streamlit are you on?

8

1.28.2

9

Must have been a dependency issue. I was on 1.28.0 so I deleted the virtual environment and reinstalled everything and now it’s working.