python - Flask app needs static files to be in two locations to show up -

i'm using send_from_directory in flask serve static js assets. app structure looks this:

/basefolder     /app         __init__.py         /js/             jquery.js     run.py     /js/         jquery.js 

the __init__.py responsible of app management , has following:

app = flask(__name__) [...] @app.route('/js/<path:path>') def send_js(path):     return send_from_directory('js',path) [...] def go():     [...]     app.run() 

the app kicks off run.py file runs go function in file above. (this mirrors app setup of app in flask web development should typical use case flask.)

theoretically, send_js function should return file either app/js/ or js/ directory. however, removing either of these files causes application 404. (the app serves contents of lower one; touch js/jquery.js in upper folder enough make things work.)

why happen?

since application runs run.py, thinks current directory @ /basefolder, application expects directory @ /basefolder/app.

adding os.chdir("app") run.py fixes this. doesn't explain why app expects different paths @ different locations, though.