Prevent purchasing multiple of the same stock per day

If someone would be able to help me to figure out the logic/how to program this.

I currently have python app that runs once per day. It screens stocks for certain criteria and then puts in a purchase order. I would like this app to be able to run multiple times per day but can’t figure out how to prevent it from ordering the same stock over and over.

I recognized that this can get closed orders:

Get the last 100 of our closed orders

closed_orders = api.list_orders(
nested=True # show nested multi-leg orders

Get only the closed orders for a particular stock

closed_aapl_orders = [o for o in closed_orders if o.symbol == ‘AAPL’]

But how can i get any open and closed orders entered today?