Import Local module while using AppTest - Error

[Ezra-Kirk]

I’m running my app locally, and want to set up a simple testing framework with the inbuilt AppTest. It is a multipage app and I’m using Poetry.

Structure:

Streamlit version: 1.28.2
Python version: 3.10.12

My entry file is the 0_X_Home.py (where X is the emoji). I’m importing my local utils package for added functionality. Here, I’m using the set_state module:

The app works fine locally using streamlit run 0_X_Home.py, but when I create the test file test_home.py and use AppTest.from_file and point to the entry file, it gives the following error when I run pytest.

2023-11-20 11:57:23.824 Uncaught app exception
Traceback (most recent call last):
  File "/home/ezra/.cache/pypoetry/virtualenvs/az-streamlit-qhVRzfSP-py3.10/lib/python3.10/site-packages/streamlit/runtime/scriptrunner/script_runner.py", line 534, in _run_script
    exec(code, module.__dict__)
  File "/home/ezra/az-streamlit/az_streamlit/0_🏠_Home.py", line 2, in <module>
    from utils import set_state
ModuleNotFoundError: No module named 'utils'

I’ve checked out some example apps but can’t figure out where I’m going wrong.

[Goyo]

Run your tests from the same directory where you are running the application.

[Ezra-Kirk]

Thanks for taking a look. I’ve tried a few different setups.

From ~/az-streamlit/az_streamlit I run either poetry run pytest or poetry run pytest test_home.py, in both cases I get the same error:

=============================================================================== FAILURES ================================================================================
__________________________________________________________________________ test_set_study_code __________________________________________________________________________

    def test_set_study_code():
        at = AppTest.from_file("0_🏠_Home.py").run()
>       assert not at.exception
E       assert not ElementList(_list=[Exception(message="No module named 'utils'", stack_trace=['File "/home/ezra/.cache/pypoetry/virtual...)', 'File "/home/ezra/az-streamlit/az_streamlit/0_🏠_Home.py", line 2, in <module>\n    from utils import set_state'])])
E        +  where ElementList(_list=[Exception(message="No module named 'utils'", stack_trace=['File "/home/ezra/.cache/pypoetry/virtual...)', 'File "/home/ezra/az-streamlit/az_streamlit/0_🏠_Home.py", line 2, in <module>\n    from utils import set_state'])]) = AppTest(_script_path='0_🏠_Home.py', default_timeout=3, session_state={$$STREAMLIT_INTERNAL_KEY_SCRIPT_RUN_WITHOUT_ERRO... 2, in <module>\n    from utils import set_state'])}), 1: SpecialBlock(type='sidebar'), 2: SpecialBlock(type='event')}).exception

test_home.py:5: AssertionError
------------------------------------------------------------------------- Captured stderr call --------------------------------------------------------------------------
2023-11-20 12:26:53.249 Uncaught app exception
Traceback (most recent call last):
  File "/home/ezra/.cache/pypoetry/virtualenvs/az-streamlit-qhVRzfSP-py3.10/lib/python3.10/site-packages/streamlit/runtime/scriptrunner/script_runner.py", line 534, in _run_script
    exec(code, module.__dict__)
  File "/home/ezra/az-streamlit/az_streamlit/0_🏠_Home.py", line 2, in <module>
    from utils import set_state
ModuleNotFoundError: No module named 'utils'
======================================================================== short test summary info ========================================================================
FAILED test_home.py::test_set_study_code - assert not ElementList(_list=[Exception(message="No module named 'utils'", stack_trace=['File "/home/ezra/.cache/pypoetry/virtual...)', 'File "/home/ezra/az-streaml...

FYI

'''test_home.py contents'''
from streamlit.testing.v1 import AppTest

def test_set_study_code():
    at = AppTest.from_file("0_🏠_Home.py").run()
    assert not at.exception

[peteratdemtec]

I was also affected by this and found a solution.

Run pytest with python and as a module:

poetry run python -m pytest

[peteratdemtec]

In fairness, I found this solution here Getting "Module not found error" when attempting to import user package · Issue #1780 · streamlit/streamlit · GitHub

[Ezra-Kirk]

Amazing - fixed it. Thank you!