feat(streamlit): setup django during init

so e.g. Django models can be queried from Streamlit apps

Author: thekaveman

streamlit_app/main.py

@@ -1,5 +1,7 @@
 import logging
+import os
 
+import django
 import streamlit as st
 
 from streamlit_app.utils import discover_apps
@@ -8,9 +10,20 @@
 logger = logging.getLogger(__name__)
 
 
+def django_setup():
+    """
+    Configures Django in case it is not running in the same environment. Should be called before using e.g. PeMS models.
+    """
+    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "pems.settings")
+
+    django.setup()
+
+
 def main():
     logger.info("Streamlit initializing")
 
+    django_setup()
+
     # find apps in the ./streamlit_app/apps directory and subdirectories
     # apps are python modules with a name starting with "app_"
     apps = discover_apps()

tests/pytest/streamlit_app/test_main.py

@@ -19,11 +19,13 @@ def test_main(mocker, monkeypatch, nav_option, expected_nav):
     else:
         monkeypatch.delenv(nav_key, False)
 
+    mock_django = mocker.patch("streamlit_app.main.django.setup")
     mock_discover = mocker.patch("streamlit_app.main.discover_apps", return_value=apps)
     mock_navigate = mocker.patch("streamlit_app.main.st.navigation")
 
     main.main()
 
+    mock_django.assert_called_once()
     mock_discover.assert_called_once()
     mock_navigate.assert_called_once_with(apps, position=expected_nav)
     mock_navigate.return_value.run.assert_called_once()