Is there a list of stocks that can be displayed as a quick filter or you want people to enter a list of stock names to a text box? Can you describe the scenario in more detail?
FYI although it's listed in the Coming Soon the Python integration is currently working on 10.1, it was announced & released just before the Tableau conference: Leverage the power of Python in Tableau with TabPy | Tableau Software
I'm with Bora on needing more info to answer the question, one key factor to keep in mind is that Tableau's Python & R integration are both designed for running Python & R on data that you have, not so much for creating new data sources or appending lots of data to existing data. In other words, you can't make more marks than you already have in your data + Tableau's data densification***. As a quick example, let's say I've got a data source with data on every stock & every day, and a data source with 10 rows. If I use that 10 row data source in Tableau then without resorting to data densification tricks I'm not going to get more than 10 marks in a single Tableau view, so I'm not going to be able to display lots and lots of daily results for lots of stocks. In that case then the Tableau data source should probably be the stock data.
*** yes there are possibly tricks with pivot and/or measure names/measure values as well.