want to create a new dict in pset7

Question

In index, how do I create a new dict which takes all the non-zero share entries to display. For example I can use stocks = db.execute and use SUM(shares) to get the total shares for each stock. But then I want to create a new dict which only has those corresponding entries and not all the ones in the table. Do I say new_stocks = {}{} or and the populate it new_stocks[row1]["shares"] = ...

thanks for any assistance.

Answer 1

Another way to accomplish this would be to select only the rows you want in the sql. You can use a HAVING clause to filter aggregate results. Something like:

SELECT SUM(shares) as hash ,symbol
from transactions
group by symbol
HAVING hash > 0

[Note: the as hash renames SUM(shares) to hash, otherwise the key in the return dictionary will be "SUM(shares)"]

Here's the sqlite doc.

new_stocks = {}{} is not valid syntax.

If you want it to be a dict, new_stocks = {} will initialize it. Then you could iterate through stocks and update it with any stock where "SUM(shares)" is not 0.

If you want it to be a list, new_stocks = [] will initialize it. Then you could iterate through stocks and append any stock where "SUM(shares)" is not 0.